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2019-12-23drm/i915/display: Prepare for fastset external dependencies checkJosé Roberto de Souza
MST and port sync have master and slaves pipes and it brings dependencies between pipes to allow fastset. For example if only MST master needs a modeset all of its slaves also needs to do a modeset. This patch adds the base for external dependencies check, the MST and port sync bits will be added in another patches. v3: - moved handling to intel_atomic_check() this way is guarantee that all pipes will have its state computed v4: - added a function to return if MST master neeeds modeset to simply code in intel_atomic_check() v5: - fixed and moved code to check if MST master needs a modeset v6: - previons version of this patch was split into two patches Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Manasi Navare <manasi.d.navare@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: José Roberto de Souza <jose.souza@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-5-jose.souza@intel.com
2019-12-23drm/i915/dp: Fix MST disable sequenceJosé Roberto de Souza
The disable sequence after wait for transcoder off was not correctly implemented. The MST disable sequence is basically the same for HSW, SKL, ICL and TGL, with just minor changes for TGL. With this last patch we finally fixed the hotplugs triggered by MST sinks during the disable/enable sequence, those were causing source to try to do a link training while it was not ready causing CPU pipe FIFO underrrus on TGL. v2: Only unsetting TGL_TRANS_DDI_PORT_MASK for TGL on the post disable sequence v4: Rebased, moved MST sequences to intel_mst_post_disable_dp() BSpec: 4231 BSpec: 4163 BSpec: 22243 BSpec: 49190 Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: José Roberto de Souza <jose.souza@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-4-jose.souza@intel.com
2019-12-23drm/i915/display: Always enables MST master pipe firstJosé Roberto de Souza
Due to DDB overlaps the pipe enabling sequence is not always crescent. As the previous patch selects the smallest pipe/transcoder in the MST stream to be master and it needs to be enabled first, this changes were needed to guarantee that. So first lets enable all pipes that do not need a fullmodeset as those don't have any external dependency and those are the ones that can overlap with each other. Then on the second loop it will enable all the pipes that needs a modeset and don't depends on other pipes like MST master pipe/transcoder. Then finally all the pipes that needs a modeset and have dependency on other pipes, that at this point are alread enabled. v3: rebased v4: - added check for modeset_pipes too to decide if is necessary for a wait a vblank - added DDB allocation overlap check for pipes that needs a modeset Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Manasi Navare <manasi.d.navare@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: José Roberto de Souza <jose.souza@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-3-jose.souza@intel.com
2019-12-23drm/i915/tgl: Select master transcoder for MST streamJosé Roberto de Souza
On TGL the blending of all the streams have moved from DDI to transcoder, so now every transcoder working over the same MST port must send its stream to a master transcoder and master will send to DDI respecting the time slots. So here adding all the CRTCs that shares the same MST stream if needed and computing their state again, it will pick the lowest pipe/transcoder among the ones in the same stream to be master. Most of the time skl_commit_modeset_enables() enables pipes in a crescent order but due DDB overlapping it might not happen, this scenarios will be handled in the next patch. v2: - Using recently added intel_crtc_state_reset() to set mst_master_transcoder to invalid transcoder for all non gen12 & MST code paths - Setting lowest pipe/transcoder as master, previously it was the first one but setting a predictable one will help in future MST e port sync integration - Moving to intel type as much as we can v3: - Now intel_dp_mst_master_trans_compute() returns the MST master transcoder - Replaced stdbool.h by linux/types.h - Skip the connector being checked in intel_dp_mst_atomic_master_trans_check() - Using pipe instead of transcoder to compute MST master v4: - renamed connector_state to conn_state v5: - Improved the parameters of intel_dp_mst_master_trans_compute() to simply code - Added call drm_atomic_add_affected_planes() in intel_dp_mst_atomic_master_trans_check() as helper could not do it for us - Removed "if (ret)" left over from v3 changes v6: - handled ret == I915_MAX_PIPES case in compute BSpec: 50493 BSpec: 49190 Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: José Roberto de Souza <jose.souza@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-2-jose.souza@intel.com
2019-12-23drm/i915/display: Share intel_connector_needs_modeset()José Roberto de Souza
intel_connector_needs_modeset() will be used outside of intel_display.c in a future patch so it would only be necessary to remove the state and add the prototype to the header file. But while at it, I simplified the arguments and moved it to a better place intel_atomic.c. No behavior changes intended here. v3: - removed digital from exported version of intel_connector_needs_modeset - rollback connector to drm type v4: - Renamed new_connector_state to new_conn_state - Going back to drm_connector_state in intel_encoders_update_prepare/complete as we also have intel_tv_connector_state Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: José Roberto de Souza <jose.souza@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-1-jose.souza@intel.com
2019-12-23drm/i915: Update DRIVER_DATE to 20191223Jani Nikula
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2019-12-23io-wq: remove unused busy list from io_sqeHillf Danton
Commit e61df66c69b1 ("io-wq: ensure free/busy list browsing see all items") added a list for io workers in addition to the free and busy lists, not only making worker walk cleaner, but leaving the busy list unused. Let's remove it. Signed-off-by: Hillf Danton <hdanton@sina.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-23cifs: Optimize readdir on reparse pointsPaulo Alcantara (SUSE)
When listing a directory with thounsands of files and most of them are reparse points, we simply marked all those dentries for revalidation and then sending additional (compounded) create/getinfo/close requests for each of them. Instead, upon receiving a response from an SMB2_QUERY_DIRECTORY (FileIdFullDirectoryInformation) command, the directory entries that have a file attribute of FILE_ATTRIBUTE_REPARSE_POINT will contain an EaSize field with a reparse tag in it, so we parse it and mark the dentry for revalidation only if it is a DFS or a symlink. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-23cifs: Adjust indentation in smb2_open_fileNathan Chancellor
Clang warns: ../fs/cifs/smb2file.c:70:3: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] if (oparms->tcon->use_resilient) { ^ ../fs/cifs/smb2file.c:66:2: note: previous statement is here if (rc) ^ 1 warning generated. This warning occurs because there is a space after the tab on this line. Remove it so that the indentation is consistent with the Linux kernel coding style and clang no longer warns. Fixes: 592fafe644bf ("Add resilienthandles mount parm") Link: https://github.com/ClangBuiltLinux/linux/issues/826 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-23libbpf: Fix build on read-only filesystemsNamhyung Kim
I got the following error when I tried to build perf on a read-only filesystem with O=dir option. $ cd /some/where/ro/linux/tools/perf $ make O=$HOME/build/perf ... CC /home/namhyung/build/perf/lib.o /bin/sh: bpf_helper_defs.h: Read-only file system make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1 make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2 make[2]: *** Waiting for unfinished jobs.... LD /home/namhyung/build/perf/libperf-in.o AR /home/namhyung/build/perf/libperf.a PERF_VERSION = 5.4.0 make[1]: *** [Makefile.perf:225: sub-make] Error 2 make: *** [Makefile:70: all] Error 2 It was becaused bpf_helper_defs.h was generated in current directory. Move it to OUTPUT directory. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191223061326.843366-1-namhyung@kernel.org
2019-12-23drm/i915: Mark the GEM context link as RCU protectedChris Wilson
The only protection for intel_context.gem_cotext is granted by RCU, so annotate it as a rcu protected pointer and carefully dereference it in the few occasions we need to use it. Fixes: 9f3ccd40acf4 ("drm/i915: Drop GEM context as a direct link from i915_request") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Andi Shyti <andi.shyti@intel.com> Acked-by: Andi Shyti <andi.shyti@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191222233558.2201901-1-chris@chris-wilson.co.uk
2019-12-23drm/i915: Introduce a vma.krefChris Wilson
Start introducing a kref on i915_vma in order to protect the vma unbind (i915_gem_object_unbind) from a parallel destruction (i915_vma_parked). Later, we will use the refcount to manage all access and turn i915_vma into a first class container. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Imre Deak <imre.deak@intel.com> Acked-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191222210256.2066451-2-chris@chris-wilson.co.uk
2019-12-23drm/i915: Add a simple is-bound check before unbindingChris Wilson
Only acquire the various atomic references required to unbind the vma if we do need to unbind the vma. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191222210256.2066451-1-chris@chris-wilson.co.uk
2019-12-23drm/i915: Hold reference to intel_frontbuffer as we track activityChris Wilson
Since obj->frontbuffer is no longer protected by the struct_mutex, as we are processing the execbuf, it may be removed. Mark the intel_frontbuffer as rcu protected, and so acquire a reference to the struct as we track activity upon it. Closes: https://gitlab.freedesktop.org/drm/intel/issues/827 Fixes: 8e7cb1799b4f ("drm/i915: Extract intel_frontbuffer active tracking") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Matthew Auld <matthew.auld@intel.com> Cc: <stable@vger.kernel.org> # v5.4+ Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191218104043.3539458-1-chris@chris-wilson.co.uk (cherry picked from commit da42104f589d979bbe402703fd836cec60befae1) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2019-12-23drm/i915/gt: Ratelimit display power w/aChris Wilson
For very light workloads that frequently park, acquiring the display power well (required to prevent the dmc from trashing the system) takes longer than the execution. A good example is the igt_coherency selftest, which is slowed down by an order of magnitude in the worst case with powerwell cycling. To prevent frequent cycling, while keeping our fast soft-rc6, use a timer to delay release of the display powerwell. Fixes: 311770173fac ("drm/i915/gt: Schedule request retirement when timeline idles") References: https://gitlab.freedesktop.org/drm/intel/issues/848 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191218093504.3477048-1-chris@chris-wilson.co.uk (cherry picked from commit 81ff52b705775433a955b2746d37b87bdc89a3d0) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2019-12-23drm/i915/pmu: Ensure monotonic rc6Tvrtko Ursulin
Avoid rc6 counter going backward in close to 0% RC6 scenarios like: 15.005477996 114,246,613 ns i915/rc6-residency/ 16.005876662 667,657 ns i915/rc6-residency/ 17.006131417 7,286 ns i915/rc6-residency/ 18.006615031 18,446,744,073,708,914,688 ns i915/rc6-residency/ 19.007158361 18,446,744,073,709,447,168 ns i915/rc6-residency/ 20.007806498 0 ns i915/rc6-residency/ 21.008227495 1,440,403 ns i915/rc6-residency/ There are two aspects to this fix. First is not assuming rc6 value zero means GT is asleep since that can also mean GPU is fully busy and we do not want to enter the estimation path in that case. Second is ensuring monotonicity on the estimation path itself. I suspect what is happening is with extremely rapid park/unpark cycles we get no updates on the real rc6 and therefore have to careful not to unconditionally trust use last known real rc6 when creating a new estimation. v2: * Simplify logic by not tracking the estimate but last reported value. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Fixes: 16ffe73c186b ("drm/i915/pmu: Use GT parked for estimating RC6 while asleep") Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> # v1 Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20191217142057.1000-1-tvrtko.ursulin@linux.intel.com (cherry picked from commit df6a42053513846475ae1fbd224dfbdbcd0c7010) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2019-12-23drm/i915: Make sure CCS YUV semiplanar format checks workImre Deak
For CCS formats, the current DRM core check for YUV semiplanar formats doesn't work; use an i915 specific function for that. v2: Fix checkpatch warnings. Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Mika Kahola <mika.kahola@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-11-imre.deak@intel.com
2019-12-23drm/i915: Make sure Y slave planes get all the required stateImre Deak
Y planes program the offset and stride of the AUX plane, so make sure we copy the required info for this into their plane state. Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Cc: Mika Kahola <mika.kahola@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-10-imre.deak@intel.com
2019-12-23drm/i915: Skip rotated offset adjustment for unsupported modifiersDhinakaran Pandiyan
During framebuffer creation, we pre-compute offsets for 90/270 plane rotation. However, only Y and Yf modifiers support 90/270 rotation. So, skip the calculations for other modifiers. To keep the gem buffer size check still working for tiled planes, factor out the logic needed for rotation setup and skip only this part for tiled planes other than Y/Yf. v2: Add a bounds check WARN for the rotation info array. v3: Keep the gem buffer size check working for tiled planes. Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Mika Kahola <mika.kahola@intel.com> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-9-imre.deak@intel.com
2019-12-23drm/i915/tgl: Make sure FBs have a correct CCS plane strideImre Deak
The CCS plane stride must be fixed on TGL, as it's not configurable for the display. Instead the HW has a hardwired logic to determine it from the main plane stride. Make sure userspace passes in the correct stride. Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Mika Kahola <mika.kahola@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-8-imre.deak@intel.com
2019-12-23drm/i915/tgl: Gen-12 render decompressionDhinakaran Pandiyan
Gen-12 display decompression operates on Y-tiled compressed main surface. The CCS is linear and has 4 bits of metadata for each main surface cache line pair, a size ratio of 1:256. Gen-12 display decompression is incompatible with buffers compressed by earlier GPUs, so make use of a new modifier to identify gen-12 compression. Another notable change is that render decompression is supported on all planes except cursor and on all pipes. Start by adding render decompression support for [A,X]BGR888 pixel formats. v2: Fix checkpatch warnings (Lucas) v3: Rebase, disable color clear, styling changes and modify intel_tile_width_bytes and intel_tile_height to handle linear CCS v4: - Use format block descriptors and the i915 specific func to get the subsampling for each color plane. - Use helpers to convert between CCS and main planes. v5: - Fix subsampling returned by intel_fb_plane_get_subsampling() for the CCS plane of the first plane. v6: - Rebased on v2 of patch 4. v7: - Fix plane dimensions during FB check. Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Nanley G Chery <nanley.g.chery@intel.com> Cc: Jason Ekstrand <jason@jlekstrand.net> Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com> (v6) Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-7-imre.deak@intel.com
2019-12-23drm/framebuffer: Format modifier for Intel Gen-12 render compressionDhinakaran Pandiyan
Gen-12 has a new compression format, add a new modifier to indicate that. Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Nanley G Chery <nanley.g.chery@intel.com> Cc: Jason Ekstrand <jason@jlekstrand.net> Cc: Mika Kahola <mika.kahola@intel.com> Cc: dri-devel@lists.freedesktop.org Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-6-imre.deak@intel.com
2019-12-23drm/i915: Add helpers to select correct ccs/aux planesImre Deak
Using helpers instead of open coding this to select a CCS plane for a main plane makes the code cleaner and less error-prone when the location of CCS plane can be different based on the format (packed vs. YUV semiplanar). The same applies to selecting an AUX plane which can be a UV plane (for an uncompressed YUV semiplanar format), or a CCS plane. Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Mika Kahola <mika.kahola@intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-5-imre.deak@intel.com
2019-12-23drm/i915: Extract framebufer CCS offset checks into a functionDhinakaran Pandiyan
intel_fill_fb_info() has grown quite large and wrapping the offset checks into a separate function makes the loop a bit easier to follow. v2: Skip the check for non-CCS planes. (Mika) Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Mika Kahola <mika.kahola@intel.com> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-4-imre.deak@intel.com
2019-12-23drm/i915: Move CCS stride alignment W/A inside intel_fb_stride_alignmentDhinakaran Pandiyan
Easier to read if all the alignment changes are in one place and contained within a function. Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Mika Kahola <mika.kahola@intel.com> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-3-imre.deak@intel.com
2019-12-23drm/i915: Use intel_tile_height() instead of re-implementingDhinakaran Pandiyan
intel_tile_dims() computes tile height using size and width, when there is already a function to do just that - intel_tile_height() Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Mika Kahola <mika.kahola@intel.com> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-2-imre.deak@intel.com
2019-12-23drm/i915/selftests: make mock_drm.h self-containedJani Nikula
Needs i915_drv.h because i915 gets dereferenced. Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191219155652.2666-2-jani.nikula@intel.com
2019-12-23drm/i915/selftests: make mock_context.h self-containedJani Nikula
Fix the forward declaration. Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191219155652.2666-1-jani.nikula@intel.com
2019-12-23powerpc/mm: Mark get_slice_psize() & slice_addr_is_low() as notraceMichael Ellerman
These slice routines are called from the SLB miss handler, which can lead to warnings from the IRQ code, because we have not reconciled the IRQ state properly: WARNING: CPU: 72 PID: 30150 at arch/powerpc/kernel/irq.c:258 arch_local_irq_restore.part.0+0xcc/0x100 Modules linked in: CPU: 72 PID: 30150 Comm: ftracetest Not tainted 5.5.0-rc2-gcc9x-g7e0165b2f1a9 #1 NIP: c00000000001d83c LR: c00000000029ab90 CTR: c00000000026cf90 REGS: c0000007eee3b960 TRAP: 0700 Not tainted (5.5.0-rc2-gcc9x-g7e0165b2f1a9) MSR: 8000000000021033 <SF,ME,IR,DR,RI,LE> CR: 22242844 XER: 20000000 CFAR: c00000000001d780 IRQMASK: 0 ... NIP arch_local_irq_restore.part.0+0xcc/0x100 LR trace_graph_entry+0x270/0x340 Call Trace: trace_graph_entry+0x254/0x340 (unreliable) function_graph_enter+0xe4/0x1a0 prepare_ftrace_return+0xa0/0x130 ftrace_graph_caller+0x44/0x94 # (get_slice_psize()) slb_allocate_user+0x7c/0x100 do_slb_fault+0xf8/0x300 instruction_access_slb_common+0x140/0x180 Fixes: 48e7b7695745 ("powerpc/64s/hash: Convert SLB miss handlers to C") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191221121337.4894-1-mpe@ellerman.id.au
2019-12-23drm/i915: fix comment for POWER_DOMAIN_TRANSCODER_VDSC_PW2Jani Nikula
The power domain covers VDSC for DSI transcoder on ICL, and it's pedantically about pipe, not transcoder, on TGL. Reported-by: Vandita Kulkarni <vandita.kulkarni@intel.com> Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191219133845.9333-1-jani.nikula@intel.com
2019-12-23arm64: dts: imx8mq-librem5-devkit: use correct interrupt for the magnetometerAngus Ainslie (Purism)
The LSM9DS1 uses a high level interrupt. Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca> Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm> Fixes: eb4ea0857c83 ("arm64: dts: fsl: librem5: Add a device tree for the Librem5 devkit") Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-23ARM: dts: imx6q-dhcom: Fix SGTL5000 VDDIO regulator connectionMarek Vasut
The SGTL5000 VDDIO is connected to the PMIC SW2 output, not to a fixed 3V3 rail. Describe this correctly in the DT. Fixes: 52c7a088badd ("ARM: dts: imx6q: Add support for the DHCOM iMX6 SoM and PDK2") Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Ludwig Zenz <lzenz@dh-electronics.com> Cc: NXP Linux Team <linux-imx@nxp.com> To: linux-arm-kernel@lists.infradead.org Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-23dmaengine: virt-dma: Fix access after free in vchan_complete()Peter Ujfalusi
vchan_vdesc_fini() is freeing up 'vd' so the access to vd->tx_result is via already freed up memory. Move the vchan_vdesc_fini() after invoking the callback to avoid this. Fixes: 09d5b702b0f97 ("dmaengine: virt-dma: store result on dma descriptor") Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20191220131100.21804-1-peter.ujfalusi@ti.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-12-23dmaengine: k3dma: Avoid null pointer traversalJohn Stultz
In some cases we seem to submit two transactions in a row, which causes us to lose track of the first. If we then cancel the request, we may still get an interrupt, which traverses a null ds_run value. So try to avoid starting a new transaction if the ds_run value is set. While this patch avoids the null pointer crash, I've had some reports of the k3dma driver still getting confused, which suggests the ds_run/ds_done value handling still isn't quite right. However, I've not run into an issue recently with it so I think this patch is worth pushing upstream to avoid the crash. Signed-off-by: John Stultz <john.stultz@linaro.org> [add ss tag] Link: https://lore.kernel.org/r/20191218190906.6641-1-john.stultz@linaro.org Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-12-23ARM: dts: imx7ulp: fix reg of cpu nodePeng Fan
According to arm cpus binding doc, " On 32-bit ARM v7 or later systems this property is required and matches the CPU MPIDR[23:0] register bits. Bits [23:0] in the reg cell must be set to bits [23:0] in MPIDR. All other bits in the reg cell must be set to 0. " In i.MX7ULP, the MPIDR[23:0] is 0xf00, not 0, so fix it. Otherwise there will be warning: "DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map" Fixes: 20434dc92c05 ("ARM: dts: imx: add common imx7ulp dtsi support") Signed-off-by: Peng Fan <peng.fan@nxp.com> Reviewed-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-23arm64: dts: imx8mm: Change SDMA1 ahb clock for imx8mmAdam Ford
Using SDMA1 with UART1 is causing a "Timeout waiting for CH0" error. This patch changes to ahb clock from SDMA1_ROOT to AHB which fixes the timeout error. Fixes: a05ea40eb384 ("arm64: dts: imx: Add i.mx8mm dtsi support") Signed-off-by: Adam Ford <aford173@gmail.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-23arm64: dts: ls1028a: fix endian setting for dcfgYinbo Zhu
DCFG block uses little endian. Fix it so that register access becomes correct. Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com> Acked-by: Yangbo Lu <yangbo.lu@nxp.com> Fixes: 8897f3255c9c ("arm64: dts: Add support for NXP LS1028A SoC") Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-23ARM: dts: imx6q-dhcom: fix rtc compatibleAlexandre Belloni
The only correct and documented compatible string for the rv3029 is microcrystal,rv3029. Fix it up. Fixes: 52c7a088badd ("ARM: dts: imx6q: Add support for the DHCOM iMX6 SoM and PDK2") Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-12-23PM / devfreq: tegra: Add COMMON_CLK dependencyArnd Bergmann
Compile-testing this driver fails if CONFIG_COMMON_CLK is not set: drivers/devfreq/tegra30-devfreq.o: In function `tegra_devfreq_target': tegra30-devfreq.c:(.text+0x164): undefined reference to `clk_set_min_rate' Fixes: 35f8dbc72721 ("PM / devfreq: tegra: Enable COMPILE_TEST for the driver") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-23PM / devfreq: Drop explicit selection of PM_OPPLeonard Crestez
CONFIG_PM_OPP is already selected by CONFIG_PM_DEVFREQ since commit b9c69e043266 ("PM / devfreq: Add dependency on PM_OPP"). This means that individual drivers shouldn't "select PM_OPP" explicitly. Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> [cw00.choi: Edit the patch title] Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-22bpf: Fix precision tracking for unbounded scalarsDaniel Borkmann
Anatoly has been fuzzing with kBdysch harness and reported a hang in one of the outcomes. Upon closer analysis, it turns out that precise scalar value tracking is missing a few precision markings for unknown scalars: 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 0: (b7) r0 = 0 1: R0_w=invP0 R1=ctx(id=0,off=0,imm=0) R10=fp0 1: (35) if r0 >= 0xf72e goto pc+0 --> only follow fallthrough 2: R0_w=invP0 R1=ctx(id=0,off=0,imm=0) R10=fp0 2: (35) if r0 >= 0x80fe0000 goto pc+0 --> only follow fallthrough 3: R0_w=invP0 R1=ctx(id=0,off=0,imm=0) R10=fp0 3: (14) w0 -= -536870912 4: R0_w=invP536870912 R1=ctx(id=0,off=0,imm=0) R10=fp0 4: (0f) r1 += r0 5: R0_w=invP536870912 R1_w=inv(id=0) R10=fp0 5: (55) if r1 != 0x104c1500 goto pc+0 --> push other branch for later analysis R0_w=invP536870912 R1_w=inv273421568 R10=fp0 6: R0_w=invP536870912 R1_w=inv273421568 R10=fp0 6: (b7) r0 = 0 7: R0=invP0 R1=inv273421568 R10=fp0 7: (76) if w1 s>= 0xffffff00 goto pc+3 --> only follow goto 11: R0=invP0 R1=inv273421568 R10=fp0 11: (95) exit 6: R0_w=invP536870912 R1_w=inv(id=0) R10=fp0 6: (b7) r0 = 0 propagating r0 7: safe processed 11 insns [...] In the analysis of the second path coming after the successful exit above, the path is being pruned at line 7. Pruning analysis found that both r0 are precise P0 and both R1 are non-precise scalars and given prior path with R1 as non-precise scalar succeeded, this one is therefore safe as well. However, problem is that given condition at insn 7 in the first run, we only followed goto and didn't push the other branch for later analysis, we've never walked the few insns in there and therefore dead-code sanitation rewrites it as goto pc-1, causing the hang depending on the skb address hitting these conditions. The issue is that R1 should have been marked as precise as well such that pruning enforces range check and conluded that new R1 is not in range of old R1. In insn 4, we mark R1 (skb) as unknown scalar via __mark_reg_unbounded() but not mark_reg_unbounded() and therefore regs->precise remains as false. Back in b5dc0163d8fd ("bpf: precise scalar_value tracking"), this was not the case since marking out of __mark_reg_unbounded() had this covered as well. Once in both are set as precise in 4 as they should have been, we conclude that given R1 was in prior fall-through path 0x104c1500 and now is completely unknown, the check at insn 7 concludes that we need to continue walking. Analysis after the fix: 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 0: (b7) r0 = 0 1: R0_w=invP0 R1=ctx(id=0,off=0,imm=0) R10=fp0 1: (35) if r0 >= 0xf72e goto pc+0 2: R0_w=invP0 R1=ctx(id=0,off=0,imm=0) R10=fp0 2: (35) if r0 >= 0x80fe0000 goto pc+0 3: R0_w=invP0 R1=ctx(id=0,off=0,imm=0) R10=fp0 3: (14) w0 -= -536870912 4: R0_w=invP536870912 R1=ctx(id=0,off=0,imm=0) R10=fp0 4: (0f) r1 += r0 5: R0_w=invP536870912 R1_w=invP(id=0) R10=fp0 5: (55) if r1 != 0x104c1500 goto pc+0 R0_w=invP536870912 R1_w=invP273421568 R10=fp0 6: R0_w=invP536870912 R1_w=invP273421568 R10=fp0 6: (b7) r0 = 0 7: R0=invP0 R1=invP273421568 R10=fp0 7: (76) if w1 s>= 0xffffff00 goto pc+3 11: R0=invP0 R1=invP273421568 R10=fp0 11: (95) exit 6: R0_w=invP536870912 R1_w=invP(id=0) R10=fp0 6: (b7) r0 = 0 7: R0_w=invP0 R1_w=invP(id=0) R10=fp0 7: (76) if w1 s>= 0xffffff00 goto pc+3 R0_w=invP0 R1_w=invP(id=0) R10=fp0 8: R0_w=invP0 R1_w=invP(id=0) R10=fp0 8: (a5) if r0 < 0x2007002a goto pc+0 9: R0_w=invP0 R1_w=invP(id=0) R10=fp0 9: (57) r0 &= -16316416 10: R0_w=invP0 R1_w=invP(id=0) R10=fp0 10: (a6) if w0 < 0x1201 goto pc+0 11: R0_w=invP0 R1_w=invP(id=0) R10=fp0 11: (95) exit 11: R0=invP0 R1=invP(id=0) R10=fp0 11: (95) exit processed 16 insns [...] Fixes: 6754172c208d ("bpf: fix precision tracking in presence of bpf2bpf calls") Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191222223740.25297-1-daniel@iogearbox.net
2019-12-22Linux 5.5-rc3v5.5-rc3Linus Torvalds
2019-12-22Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull vfs fixes from Al Viro: "Eric's s_inodes softlockup fixes + Jan's fix for recent regression from pipe rework" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: call fsnotify_sb_delete after evict_inodes fs: avoid softlockups in s_inodes iterators pipe: Fix bogus dereference in iov_iter_alignment()
2019-12-22Merge tag 'xfs-5.5-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull xfs fixes from Darrick Wong: "Fix a few bugs that could lead to corrupt files, fsck complaints, and filesystem crashes: - Minor documentation fixes - Fix a file corruption due to read racing with an insert range operation. - Fix log reservation overflows when allocating large rt extents - Fix a buffer log item flags check - Don't allow administrators to mount with sunit= options that will cause later xfs_repair complaints about the root directory being suspicious because the fs geometry appeared inconsistent - Fix a non-static helper that should have been static" * tag 'xfs-5.5-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: Make the symbol 'xfs_rtalloc_log_count' static xfs: don't commit sunit/swidth updates to disk if that would cause repair failures xfs: split the sunit parameter update into two parts xfs: refactor agfl length computation function libxfs: resync with the userspace libxfs xfs: use bitops interface for buf log item AIL flag check xfs: fix log reservation overflows when allocating large rt extents xfs: stabilize insert range start boundary to avoid COW writeback race xfs: fix Sphinx documentation warning
2019-12-22Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 bug fixes from Ted Ts'o: "Ext4 bug fixes, including a regression fix" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: clarify impact of 'commit' mount option ext4: fix unused-but-set-variable warning in ext4_add_entry() jbd2: fix kernel-doc notation warning ext4: use RCU API in debug_print_tree ext4: validate the debug_want_extra_isize mount option at parse time ext4: reserve revoke credits in __ext4_new_inode ext4: unlock on error in ext4_expand_extra_isize() ext4: optimize __ext4_check_dir_entry() ext4: check for directory entries too close to block end ext4: fix ext4_empty_dir() for directories with holes
2019-12-22Merge tag 'block-5.5-20191221' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "Let's try this one again, this time without the compat_ioctl changes. We've got those fixed up, but that can go out next week. This contains: - block queue flush lockdep annotation (Bart) - Type fix for bsg_queue_rq() (Bart) - Three dasd fixes (Stefan, Jan) - nbd deadlock fix (Mike) - Error handling bio user map fix (Yang) - iocost fix (Tejun) - sbitmap waitqueue addition fix that affects the kyber IO scheduler (David)" * tag 'block-5.5-20191221' of git://git.kernel.dk/linux-block: sbitmap: only queue kyber's wait callback if not already active block: fix memleak when __blk_rq_map_user_iov() is failed s390/dasd: fix typo in copyright statement s390/dasd: fix memleak in path handling error case s390/dasd/cio: Interpret ccw_device_get_mdc return value correctly block: Fix a lockdep complaint triggered by request queue flushing block: Fix the type of 'sts' in bsg_queue_rq() block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT nbd: fix shutdown and recv work deadlock v2 iocost: over-budget forced IOs should schedule async delay
2019-12-22Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "PPC: - Fix a bug where we try to do an ultracall on a system without an ultravisor KVM: - Fix uninitialised sysreg accessor - Fix handling of demand-paged device mappings - Stop spamming the console on IMPDEF sysregs - Relax mappings of writable memslots - Assorted cleanups MIPS: - Now orphan, James Hogan is stepping down x86: - MAINTAINERS change, so long Radim and thanks for all the fish - supported CPUID fixes for AMD machines without SPEC_CTRL" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: MAINTAINERS: remove Radim from KVM maintainers MAINTAINERS: Orphan KVM for MIPS kvm: x86: Host feature SSBD doesn't imply guest feature AMD_SSBD kvm: x86: Host feature SSBD doesn't imply guest feature SPEC_CTRL_SSBD KVM: PPC: Book3S HV: Don't do ultravisor calls on systems without ultravisor KVM: arm/arm64: Properly handle faulting of device mappings KVM: arm64: Ensure 'params' is initialised when looking up sys register KVM: arm/arm64: Remove excessive permission check in kvm_arch_prepare_memory_region KVM: arm64: Don't log IMP DEF sysreg traps KVM: arm64: Sanely ratelimit sysreg messages KVM: arm/arm64: vgic: Use wrapper function to lock/unlock all vcpus in kvm_vgic_create() KVM: arm/arm64: vgic: Fix potential double free dist->spis in __kvm_vgic_destroy() KVM: arm/arm64: Get rid of unused arg in cpu_init_hyp_mode()
2019-12-22Merge tag 'riscv/for-v5.5-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Paul Walmsley: "Several fixes, and one cleanup, for RISC-V. Fixes: - Fix an error in a Kconfig file that resulted in an undefined Kconfig option "CONFIG_CONFIG_MMU" - Fix undefined Kconfig option "CONFIG_CONFIG_MMU" - Fix scratch register clearing in M-mode (affects nommu users) - Fix a mismerge on my part that broke the build for CONFIG_SPARSEMEM_VMEMMAP users Cleanup: - Move SiFive L2 cache-related code to drivers/soc, per request" * tag 'riscv/for-v5.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: move sifive_l2_cache.c to drivers/soc riscv: define vmemmap before pfn_to_page calls riscv: fix scratch register clearing in M-mode. riscv: Fix use of undefined config option CONFIG_CONFIG_MMU
2019-12-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Several nf_flow_table_offload fixes from Pablo Neira Ayuso, including adding a missing ipv6 match description. 2) Several heap overflow fixes in mwifiex from qize wang and Ganapathi Bhat. 3) Fix uninit value in bond_neigh_init(), from Eric Dumazet. 4) Fix non-ACPI probing of nxp-nci, from Stephan Gerhold. 5) Fix use after free in tipc_disc_rcv(), from Tuong Lien. 6) Enforce limit of 33 tail calls in mips and riscv JIT, from Paul Chaignon. 7) Multicast MAC limit test is off by one in qede, from Manish Chopra. 8) Fix established socket lookup race when socket goes from TCP_ESTABLISHED to TCP_LISTEN, because there lacks an intervening RCU grace period. From Eric Dumazet. 9) Don't send empty SKBs from tcp_write_xmit(), also from Eric Dumazet. 10) Fix active backup transition after link failure in bonding, from Mahesh Bandewar. 11) Avoid zero sized hash table in gtp driver, from Taehee Yoo. 12) Fix wrong interface passed to ->mac_link_up(), from Russell King. 13) Fix DSA egress flooding settings in b53, from Florian Fainelli. 14) Memory leak in gmac_setup_txqs(), from Navid Emamdoost. 15) Fix double free in dpaa2-ptp code, from Ioana Ciornei. 16) Reject invalid MTU values in stmmac, from Jose Abreu. 17) Fix refcount leak in error path of u32 classifier, from Davide Caratti. 18) Fix regression causing iwlwifi firmware crashes on boot, from Anders Kaseorg. 19) Fix inverted return value logic in llc2 code, from Chan Shu Tak. 20) Disable hardware GRO when XDP is attached to qede, frm Manish Chopra. 21) Since we encode state in the low pointer bits, dst metrics must be at least 4 byte aligned, which is not necessarily true on m68k. Add annotations to fix this, from Geert Uytterhoeven. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (160 commits) sfc: Include XDP packet headroom in buffer step size. sfc: fix channel allocation with brute force net: dst: Force 4-byte alignment of dst_metrics selftests: pmtu: fix init mtu value in description hv_netvsc: Fix unwanted rx_table reset net: phy: ensure that phy IDs are correctly typed mod_devicetable: fix PHY module format qede: Disable hardware gro when xdp prog is installed net: ena: fix issues in setting interrupt moderation params in ethtool net: ena: fix default tx interrupt moderation interval net/smc: unregister ib devices in reboot_event net: stmmac: platform: Fix MDIO init for platforms without PHY llc2: Fix return statement of llc_stat_ev_rx_null_dsap_xid_c (and _test_c) net: hisilicon: Fix a BUG trigered by wrong bytes_compl net: dsa: ksz: use common define for tag len s390/qeth: don't return -ENOTSUPP to userspace s390/qeth: fix promiscuous mode after reset s390/qeth: handle error due to unsupported transport mode cxgb4: fix refcount init for TC-MQPRIO offload tc-testing: initial tdc selftests for cls_u32 ...
2019-12-22pipe: fix empty pipe check in pipe_write()Jan Stancek
LTP pipeio_1 test is hanging with v5.5-rc2-385-gb8e382a185eb, with read side observing empty pipe and sleeping and write side running out of space and then sleeping as well. In this scenario there are 5 writers and 1 reader. Problem is that after pipe_write() reacquires pipe lock, it re-checks for empty pipe with potentially stale 'head' and doesn't wake up read side anymore. pipe->tail can advance beyond 'head', because there are multiple writers. Use pipe->head for empty pipe check after reacquiring lock to observe current state. Testing: With patch, LTP pipeio_1 ran successfully in loop for 1 hour. Without patch it hanged within a minute. Fixes: 1b6b26ae7053 ("pipe: fix and clarify pipe write wakeup logic") Reported-by: Rachel Sibley <rasibley@redhat.com> Signed-off-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>