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path: root/drivers/gpu/drm/display/drm_dp_helper.c
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2023-06-01drm/display/dp_mst: Replace all non-returning strlcpy with strscpyAzeem Shaikh
strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230522155124.2336545-1-azeemshaikh38@gmail.com
2022-10-07Merge tag 'driver-core-6.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the big set of driver core and debug printk changes for 6.1-rc1. Included in here is: - dynamic debug updates for the core and the drm subsystem. The drm changes have all been acked by the relevant maintainers - kernfs fixes for syzbot reported problems - kernfs refactors and updates for cgroup requirements - magic number cleanups and removals from the kernel tree (they were not being used and they really did not actually do anything) - other tiny cleanups All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (74 commits) docs: filesystems: sysfs: Make text and code for ->show() consistent Documentation: NBD_REQUEST_MAGIC isn't a magic number a.out: restore CMAGIC device property: Add const qualifier to device_get_match_data() parameter drm_print: add _ddebug descriptor to drm_*dbg prototypes drm_print: prefer bare printk KERN_DEBUG on generic fn drm_print: optimize drm_debug_enabled for jump-label drm-print: add drm_dbg_driver to improve namespace symmetry drm-print.h: include dyndbg header drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro drm_print: interpose drm_*dbg with forwarding macros drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers. drm_print: condense enum drm_debug_category debugfs: use DEFINE_SHOW_ATTRIBUTE to define debugfs_regset32_fops driver core: use IS_ERR_OR_NULL() helper in device_create_groups_vargs() Documentation: ENI155_MAGIC isn't a magic number Documentation: NBD_REPLY_MAGIC isn't a magic number nbd: remove define-only NBD_MAGIC, previously magic number Documentation: FW_HEADER_MAGIC isn't a magic number Documentation: EEPROM_MAGIC_VALUE isn't a magic number ...
2022-09-28drm/dp: Don't rewrite link config when setting phy test patternKhaled Almahallawy
The sequence for Source DP PHY CTS automation is [2][1]: 1- Emulate successful Link Training(LT) 2- Short HPD and change link rates and number of lanes by LT. (This is same flow for Link Layer CTS) 3- Short HPD and change PHY test pattern and swing/pre-emphasis levels (This step should not trigger LT) The problem is with DP PHY compliance setup as follow: [DPTX + on board LTTPR]------Main Link--->[Scope] ^ | | | | | ----------Aux Ch------>[Aux Emulator] At step 3, before writing TRAINING_LANEx_SET/LINK_QUAL_PATTERN_SET to declare the pattern/swing requested by scope, we write link config in LINK_BW_SET/LANE_COUNT_SET on a port that has LTTPR. As LTTPR snoops aux transaction, LINK_BW_SET/LANE_COUNT_SET writes indicate a LT will start [Check DP 2.0 E11 -Sec 3.6.8.2 & 3.6.8.6.3], and LTTPR will reset the link and stop sending DP signals to DPTX/Scope causing the measurements to fail. Note that step 3 will not trigger LT and DP link will never recovered by the Aux Emulator/Scope. The reset of link can be tested with a monitor connected to LTTPR port simply by writing to LINK_BW_SET or LANE_COUNT_SET as follow igt/tools/dpcd_reg write --offset=0x100 --value 0x14 --device=2 OR printf '\x14' | sudo dd of=/dev/drm_dp_aux2 bs=1 count=1 conv=notrunc seek=$((0x100)) This single aux write causes the screen to blank, sending short HPD to DPTX, setting LINK_STATUS_UPDATE = 1 in DPCD 0x204, and triggering LT. As stated in [1]: "Before any TX electrical testing can be performed, the link between a DPTX and DPRX (in this case, a piece of test equipment), including all LTTPRs within the path, shall be trained as defined in this Standard." In addition, changing Phy pattern/Swing/Pre-emphasis (Step 3) uses the same link rate and lane count applied on step 2, so no need to redo LT. The fix is to not rewrite link config in step 3, and just writes TRAINING_LANEx_SET and LINK_QUAL_PATTERN_SET [1]: DP 2.0 E11 - 3.6.11.1 LTTPR DPTX_PHY Electrical Compliance [2]: Configuring UnigrafDPTC Controller - Automation Test Sequence https://www.keysight.com/us/en/assets/9922-01244/help-files/ D9040DPPC-DisplayPort-Test-Software-Online-Help-latest.chm Cc: Imre Deak <imre.deak@intel.com> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Or Cochvi <or.cochvi@intel.com> Signed-off-by: Khaled Almahallawy <khaled.almahallawy@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220916054900.415804-1-khaled.almahallawy@intel.com
2022-09-24drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers.Jim Cromie
Use DECLARE_DYNDBG_CLASSMAP across DRM: - in .c files, since macro defines/initializes a record - in drivers, $mod_{drv,drm,param}.c ie where param setup is done, since a classmap is param related - in drm/drm_print.c since existing __drm_debug param is defined there, and we ifdef it, and provide an elaborated alternative. - in drm_*_helper modules: dp/drm_dp - 1st item in makefile target drivers/gpu/drm/drm_crtc_helper.c - random pick iirc. Since these modules all use identical CLASSMAP declarations (ie: names and .class_id's) they will all respond together to "class DRM_UT_*" query-commands: :#> echo class DRM_UT_KMS +p > /proc/dynamic_debug/control NOTES: This changes __drm_debug from int to ulong, so BIT() is usable on it. DRM's enum drm_debug_category values need to sync with the index of their respective class-names here. Then .class_id == category, and dyndbg's class FOO mechanisms will enable drm_dbg(DRM_UT_KMS, ...). Though DRM needs consistent categories across all modules, thats not generally needed; modules X and Y could define FOO differently (ie a different NAME => class_id mapping), changes are made according to each module's private class-map. No callsites are actually selected by this patch, since none are class'd yet. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20220912052852.1123868-3-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30drm/dp: add drm_dp_phy_name() for getting DP PHY nameJani Nikula
Add a helper for getting the DP PHY name. In the interest of caller simplicity and to avoid allocations and passing in of buffers, duplicate the const strings to return. It's a minor penalty to pay for simplicity in all the call sites. v2: Rebase, add kernel-doc, ensure non-NULL always Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/b08dc12a7e621a48ec35546d6cd1ed4b1434810d.1660553850.git.jani.nikula@intel.com
2022-07-19drm:delete the repeated word "the" in commentsshaomin Deng
remove the rebundant word "the" from comments. Signed-off-by: shaomin Deng <dengshaomin@cdjrlc.com> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220718151154.9628-1-dengshaomin@cdjrlc.com
2022-07-05drm: Remove linux/fb.h from drm_crtc.hVille Syrjälä
drm_crtc.h has no need for linux/fb.h, so don't include it. Avoids useless rebuilds of the entire universe when touching linux/fb.h. Quite a few placs do currently depend on linux/fb.h or other headers pulled in by it without actually including any of it directly. All of those need to be fixed up. v2: Split the vmwgfx change out Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220630195114.17407-3-ville.syrjala@linux.intel.com
2022-06-21drm/display: Remove duplicate 'the' in two places.Jiang Jian
there is an unexpected word "the" in the comments that need to be dropped file: drivers/gpu/drm/display/drm_dp_helper.c line: 1600 * Doesn't account the the "MOT" bit, and instead assumes each changed to * Doesn't account the "MOT" bit, and instead assumes eac Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220621190055.8323-1-jiangjian@cdjrlc.com
2022-06-20drm: Drop drm_edid.h from drm_crtc.hVille Syrjälä
drm_crtc.h has no need for drm_edid.h, so don't include it. Avoids useless rebuilds of the entire universe when touching drm_edid.h. Quite a few placs do currently depend on drm_edid.h without actually including it directly. All of those need to be fixed up. v2: Fix up i915 and msm some more v3: Fix alphabetical ordering (Sam) Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220614090245.30283-1-ville.syrjala@linux.intel.com Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Jani Nikula <jani.nikula@intel.com>
2022-04-25drm/display: Introduce a DRM display-helper moduleThomas Zimmermann
Replace the DP-helper module with a display-helper module. The support for DisplayPort becomes an internal option that drivers have to select. Update all related Kconfig and Makefile rules. Besides the existing code for DisplayPort, the new module will contain helpers for other video-output standards, such as HDMI. Drivers will have to select their required video-output helpers. Linking all display-related code into a single module avoids the proliferation of small kernel modules. The module parameters drm_dp_cec_unregister_delay, dp_aux_i2c_speed_khz, and dp_aux_i2c_transfer_size are moving from the drm_dp_helper namespace to drm_display_helper. v2: * mention module parameters in commit message (Javier) * distiguish between display module and DP support in Kconfig * update Makefile rules for DP helpers * move Kconfig rules into separate file under display/ Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-4-tzimmermann@suse.de