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Remove the code to sync the vmalloc and ioremap ranges for x86-64. The
page-table pages are all pre-allocated now so that synchronization is
no longer necessary.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20200721095953.6218-3-joro@8bytes.org
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Pre-allocate the page-table pages for the vmalloc area at the level
which needs synchronization on x86-64, which is P4D for 5-level and
PUD for 4-level paging.
Doing this at boot makes sure no synchronization of that area is
necessary at runtime. The synchronization takes the pgd_lock and
iterates over all page-tables in the system, so it can take quite long
and is better avoided.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20200721095953.6218-2-joro@8bytes.org
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Fold acpi_os_map_cleanup_deferred() into acpi_os_map_remove() and
pass the latter to INIT_RCU_WORK() in acpi_os_drop_map_ref() to make
the code more straightforward.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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There is no reason (knwon to me) why any of the existing users of
acpi_os_unmap_iomem() would need to wait for the unused memory
mappings left by it to actually go away, so use the deferred
unmapping of ACPI memory introduced previously in that function.
While at it, fold __acpi_os_unmap_iomem() back into
acpi_os_unmap_iomem(), which has become a simple wrapper around it,
and make acpi_os_unmap_memory() call the latter.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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There is no reason (knwon to me) why any of the existing users of
acpi_os_unmap_generic_address() would need to wait for the unused
memory mappings left by it to actually go away, so use the deferred
unmapping of ACPI memory introduced previously in that function.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The ACPICA's strategy with respect to the handling of memory mappings
associated with memory operation regions is to avoid mapping the
entire region at once which may be problematic at least in principle
(for example, it may lead to conflicts with overlapping mappings
having different attributes created by drivers). It may also be
wasteful, because memory opregions on some systems take up vast
chunks of address space while the fields in those regions actually
accessed by AML are sparsely distributed.
For this reason, a one-page "window" is mapped for a given opregion
on the first memory access through it and if that "window" does not
cover an address range accessed through that opregion subsequently,
it is unmapped and a new "window" is mapped to replace it. Next,
if the new "window" is not sufficient to acess memory through the
opregion in question in the future, it will be replaced with yet
another "window" and so on. That may lead to a suboptimal sequence
of memory mapping and unmapping operations, for example if two fields
in one opregion separated from each other by a sufficiently wide
chunk of unused address space are accessed in an alternating pattern.
The situation may still be suboptimal if the deferred unmapping
introduced previously is supported by the OS layer. For instance,
the alternating memory access pattern mentioned above may produce
a relatively long list of mappings to release with substantial
duplication among the entries in it, which could be avoided if
acpi_ex_system_memory_space_handler() did not release the mapping
used by it previously as soon as the current access was not covered
by it.
In order to improve that, modify acpi_ex_system_memory_space_handler()
to preserve all of the memory mappings created by it until the memory
regions associated with them go away.
Accordingly, update acpi_ev_system_memory_region_setup() to unmap all
memory associated with memory opregions that go away.
Reported-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Xiang Li <xiang.z.li@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The ACPI OS layer in Linux uses RCU to protect the walkers of the
list of ACPI memory mappings from seeing an inconsistent state
while it is being updated. Among other situations, that list can
be walked in (NMI and non-NMI) interrupt context, so using a
sleeping lock to protect it is not an option.
However, performance issues related to the RCU usage in there
appear, as described by Dan Williams:
"Recently a performance problem was reported for a process invoking
a non-trival ASL program. The method call in this case ends up
repetitively triggering a call path like:
acpi_ex_store
acpi_ex_store_object_to_node
acpi_ex_write_data_to_field
acpi_ex_insert_into_field
acpi_ex_write_with_update_rule
acpi_ex_field_datum_io
acpi_ex_access_region
acpi_ev_address_space_dispatch
acpi_ex_system_memory_space_handler
acpi_os_map_cleanup.part.14
_synchronize_rcu_expedited.constprop.89
schedule
The end result of frequent synchronize_rcu_expedited() invocation is
tiny sub-millisecond spurts of execution where the scheduler freely
migrates this apparently sleepy task. The overhead of frequent
scheduler invocation multiplies the execution time by a factor
of 2-3X."
The source of this is that acpi_ex_system_memory_space_handler()
unmaps the memory mapping currently cached by it at the access time
if that mapping doesn't cover the memory area being accessed.
Consequently, if there is a memory opregion with two fields
separated from each other by an unused chunk of address space that
is large enough for not being covered by a single mapping, and they
happen to be used in an alternating pattern, the unmapping will
occur on every acpi_ex_system_memory_space_handler() invocation for
that memory opregion and that will lead to significant overhead.
Moreover, acpi_ex_system_memory_space_handler() carries out the
memory unmapping with the namespace and interpreter mutexes held
which may lead to additional latency, because all of the tasks
wanting to acquire on of these mutexes need to wait for the
memory unmapping operation to complete.
To address that, rework acpi_os_unmap_memory() so that it does not
release the memory mapping covering the given address range right
away and instead make it queue up the mapping at hand for removal
via queue_rcu_work().
Reported-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Xiang Li <xiang.z.li@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Add dedicated Krzysztof Kozlowski's Git repository on @kernel.org for
memory controller drivers.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Fix firwmare -> firmware.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
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Remove unneeded blank line and align indentation with open parenthesis.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Align indentation with open parenthesis (or fix existing alignment).
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Macros arguments should be enclosed by parenthesis for safety.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Use proper kerneldoc to fix GCC warnings like:
drivers/memory/of_memory.c:30: warning: Function parameter or member 'dev' not described in 'of_get_min_tck'
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Fix arbitary -> arbitrary.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Remove some unneeded blank lines, align indentation with open
parenthesis (or fix existing alignment).
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Driver uses 'unsigned int' in other places instead of 'unsigned'.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Macros arguments should be enclosed by parenthesis for safety.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Use proper kerneldoc to fix GCC warnings like:
drivers/memory/omap-gpmc.c:299: warning: Function parameter or member 'cs' not described in 'gpmc_get_clk_period'
drivers/memory/omap-gpmc.c:432: warning: Excess function parameter 'ma' description in 'get_gpmc_timing_reg'
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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The line continuation contained spaces but still failed to properly
align with open parenthesis.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Add missing braces to all arms of if statement to align with coding
convention.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Add blank lines to improve code readability. No functional change.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Let's avoid memset(PAGE_UNUSED) when adding consecutive sections,
whereby the vmemmap of a single section does not span full PMDs.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-10-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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With a memmap size of 56 bytes or 72 bytes per page, the memmap for a
256 MB section won't span full PMDs. As we populate single sections and
depopulate single sections, the depopulation step would not be able to
free all vmemmap pmds anymore.
Do it similarly to x86, marking the unused memmap ranges in a special way
(pad it with 0xFD).
This allows us to add/remove sections, cleaning up all allocated
vmemmap pages even if the memmap size is not multiple of 16 bytes per page.
A 56 byte memmap can, for example, be created with !CONFIG_MEMCG and
!CONFIG_SLUB.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-9-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Let's fallback to single pages if short on huge pages. No need to stop
memory hotplug.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-8-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Let's cleanup empty page tables. Consider only page tables that fully
fall into the idendity mapping and the vmemmap range.
As there are no valid accesses to vmem/vmemmap within non-populated ranges,
the single tlb flush at the end should be sufficient.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-7-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Let's synchronize all accesses to the 1:1 and vmemmap mappings. This will
be especially relevant when wanting to cleanup empty page tables that could
be shared by both. Avoid races when removing tables that might be just
about to get reused.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-6-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Cleanup what we partially added in case vmemmap_populate() fails. For
vmem, this is already handled by vmem_add_mapping().
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-5-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Extend our shiny new modify_pagetable() to handle !direct (vmemmap)
mappings. Convert vmemmap_populate() and implement vmemmap_free().
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-4-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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We want to have only a single pagetable walker and reuse the same
functionality for vmemmap handling. Let's start by consolidating
vmem_add_range() and vmem_remove_range(), converting it into a
recursive implementation.
A recursive implementation makes it easier to expand individual cases
without harming readability. In addition, we minimize traversing the
whole hierarchy over and over again.
One change is that we don't unmap large PMDs/PUDs when not completely
covered by the request, something that should never happen with direct
mappings, unless one would be removing in other granularity than added,
which would be broken already.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-3-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Let's match the name to vmem_remove_range().
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-2-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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This kernel feature is required for enabling BPF_KPROBE_OVERRIDE.
Define override_function_with_return() and regs_set_return_value()
functions, and fix compile errors in syscall_wrapper.h.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The existing comment was talking about reading in the write part
and vice versa. While we are here make it more clear why restricting
the syscalls to MIO capable devices is okay.
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The return type of functions _inb, _inw and _inl are all u16 which looks
wrong. This patch makes them u8, u16 and u32 respectively.
The original commit text for these does not indicate that these should
be all forced to u16.
Fixes: f009c89df79a ("io: Provide _inX() and _outX()")
Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Commit 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the
caller") removed the local_irq_disable from hash_preload, but it was
required for more than just the page table walk: the hash pte busy bit is
effectively a lock which may be taken in interrupt context, and the local
update flag test must not be preempted before it's used.
This solves apparent lockups with perf interrupting __hash_page_64K. If
get_perf_callchain then also takes a hash fault on the same page while it
is already locked, it will loop forever taking hash faults, which looks like
this:
cpu 0x49e: Vector: 100 (System Reset) at [c00000001a4f7d70]
pc: c000000000072dc8: hash_page_mm+0x8/0x800
lr: c00000000000c5a4: do_hash_page+0x24/0x38
sp: c0002ac1cc69ac70
msr: 8000000000081033
current = 0xc0002ac1cc602e00
paca = 0xc00000001de1f280 irqmask: 0x03 irq_happened: 0x01
pid = 20118, comm = pread2_processe
Linux version 5.8.0-rc6-00345-g1fad14f18bc6
49e:mon> t
[c0002ac1cc69ac70] c00000000000c5a4 do_hash_page+0x24/0x38 (unreliable)
--- Exception: 300 (Data Access) at c00000000008fa60 __copy_tofrom_user_power7+0x20c/0x7ac
[link register ] c000000000335d10 copy_from_user_nofault+0xf0/0x150
[c0002ac1cc69af70] c00032bf9fa3c880 (unreliable)
[c0002ac1cc69afa0] c000000000109df0 read_user_stack_64+0x70/0xf0
[c0002ac1cc69afd0] c000000000109fcc perf_callchain_user_64+0x15c/0x410
[c0002ac1cc69b060] c000000000109c00 perf_callchain_user+0x20/0x40
[c0002ac1cc69b080] c00000000031c6cc get_perf_callchain+0x25c/0x360
[c0002ac1cc69b120] c000000000316b50 perf_callchain+0x70/0xa0
[c0002ac1cc69b140] c000000000316ddc perf_prepare_sample+0x25c/0x790
[c0002ac1cc69b1a0] c000000000317350 perf_event_output_forward+0x40/0xb0
[c0002ac1cc69b220] c000000000306138 __perf_event_overflow+0x88/0x1a0
[c0002ac1cc69b270] c00000000010cf70 record_and_restart+0x230/0x750
[c0002ac1cc69b620] c00000000010d69c perf_event_interrupt+0x20c/0x510
[c0002ac1cc69b730] c000000000027d9c performance_monitor_exception+0x4c/0x60
[c0002ac1cc69b750] c00000000000b2f8 performance_monitor_common_virt+0x1b8/0x1c0
--- Exception: f00 (Performance Monitor) at c0000000000cb5b0 pSeries_lpar_hpte_insert+0x0/0x160
[link register ] c0000000000846f0 __hash_page_64K+0x210/0x540
[c0002ac1cc69ba50] 0000000000000000 (unreliable)
[c0002ac1cc69bb00] c000000000073ae0 update_mmu_cache+0x390/0x3a0
[c0002ac1cc69bb70] c00000000037f024 wp_page_copy+0x364/0xce0
[c0002ac1cc69bc20] c00000000038272c do_wp_page+0xdc/0xa60
[c0002ac1cc69bc70] c0000000003857bc handle_mm_fault+0xb9c/0x1b60
[c0002ac1cc69bd50] c00000000006c434 __do_page_fault+0x314/0xc90
[c0002ac1cc69be20] c00000000000c5c8 handle_page_fault+0x10/0x2c
--- Exception: 300 (Data Access) at 00007fff8c861fe8
SP (7ffff6b19660) is in userspace
Fixes: 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the caller")
Reported-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reported-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200727060947.10060-1-npiggin@gmail.com
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Mention why we open-code strsep, so it is clear that it is intentional.
Fixes: 736bb11898ef ("modpost: remove use of non-standard strsep() in HOSTCC code")
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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A couple of fixes for issues relating to format modifiers (there's
still a patch pending from James Jones to hopefully address the
remaining ones), regression fix from the recent HDA nightmare, and a
race fix for Turing modesetting.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Ben Skeggs <skeggsb@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ <CACAvsv5aAp+FZMZGTB+Nszc==h5gEbdNV58sSRRQDF1R5qQRGg@mail.gmail.com
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s/postive/positive/
Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
Link: https://lore.kernel.org/r/20200724090531.GA14409@amd
[christian.brauner@ubuntu.com: tweak commit message]
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild into master
Pull Kbuild fixes from Masahiro Yamada:
- do not use non-portable strsep() in a host program
- fix single target builds for external modules
- change Clang's --prefix option to make it work for the latest Clang
* tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilation
kbuild: fix single target builds for external modules
modpost: remove use of non-standard strsep() in HOSTCC code
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Whenever a display update was sent, apart from updating
the memory base address, we called mcde_display_send_one_frame()
which also sent a command to the display requesting the TE IRQ
and enabling the FIFO.
When continuous updates are running this is wrong: we need
to only send this to start the flow to the display on
the very first update. This lead to the display pipeline
locking up and crashing.
Check if the flow is already running and in that case
do not call mcde_display_send_one_frame().
This fixes crashes on the Samsung GT-S7710 (Skomer).
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Stephan Gerhold <stephan@gerhold.net>
Cc: Stephan Gerhold <stephan@gerhold.net>
Cc: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20200718233323.3407670-1-linus.walleij@linaro.org
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git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux into master
Pull parisc fixes from Helge Deller:
"Two fixes:
- Add the cmpxchg() function for pointers to u8 values. This fixes a
kernel linking error when building the tusb1210 driver (from Liam
Beguin).
- Add a define for atomic64_set_release() to fix CPU soft lockups
which happen because of missing unlocks while processing bit
operations (from John David Anglin)"
* 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Add atomic64_set_release() define to avoid CPU soft lockups
parisc: add support for cmpxchg on u8 pointers
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The pointer bitmap is being initialized with a plain integer 0,
fix this by initializing it with a NULL instead.
Cleans up sparse warning:
arch/x86/xen/enlighten_pv.c:876:27: warning: Using plain integer
as NULL pointer
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20200721100217.407975-1-colin.king@canonical.com
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Refresh the branch for a dependent commit.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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We don't create a connector but let panel_bridge handle that so there's
no point in rejecting DRM_BRIDGE_ATTACH_NO_CONNECTOR.
Signed-off-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/8b6545b991afce6add0a24f5f5d116778b0cb763.1595096667.git.agx@sigxcpu.org
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Fine tune the HBP and HFP to avoid the dot noise on the left and right edges.
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200714123332.37609-1-jitao.shi@mediatek.com
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On boe_nv133fhm_n62 (and presumably on boe_nv133fhm_n61) a scope shows
a small spike on the HPD line right when you power the panel on. The
picture looks something like this:
+--------------------------------------
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Power ---+
+---
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+----+| |
HPD -----+ +---------------------------+
So right when power is applied there's a little bump in HPD and then
there's small spike right before it goes low. The total time of the
little bump plus the spike was measured on one panel as being 8 ms
long. The total time for the HPD to go high on the same panel was
51.2 ms, though the datasheet only promises it is < 200 ms.
When asked about this glitch, BOE indicated that it was expected and
persisted until the TCON has been initialized.
If this was a real hotpluggable DP panel then this wouldn't matter a
whole lot. We'd debounce the HPD signal for a really long time and so
the little blip wouldn't hurt. However, this is not a hotpluggable DP
panel and the the debouncing logic isn't needed and just shows down
the time needed to get the display working. This is why the code in
panel_simple_prepare() doesn't do debouncing and just waits for HPD to
go high once. Unfortunately if we get unlucky and happen to poll the
HPD line right at the spike we can try talking to the panel before
it's ready.
Let's handle this situation by putting in a 15 ms prepare delay and
decreasing the "hpd absent delay" by 15 ms. That means:
* If you don't have HPD hooked up at all you've still got the
hardcoded 200 ms delay.
* If you've got HPD hooked up you will always wait at least 15 ms
before checking HPD. The only case where this could be bad is if
the panel is sharing a voltage rail with something else in the
system and was already turned on long before the panel came up. In
such a case we'll be delaying 15 ms for no reason, but it's not a
huge delay and I don't see any other good solution to handle that
case.
Even though the delay was measured as 8 ms, 15 ms was chosen to give a
bit of margin.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200716132120.1.I01e738cd469b61fc9b28b3ef1c6541a4f48b11bf@changeid
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After the drm_bridge_connector_init() helper function has been added,
the ADV driver has been changed accordingly. However, the 'type'
field of the bridge structure was left unset, which makes the helper
function always return -EINVAL.
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@nxp.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Vinod Koul <vkoul@kernel.org> # tested on DragonBoard 410c
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200720124228.12552-1-laurentiu.palcu@oss.nxp.com
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc into master
Pull char/misc driver fixes from Greg KH:
"Here are a few small driver fixes for 5.8-rc7
They include:
- habanalabs fixes
- tiny fpga driver fixes
- /dev/mem fixup from previous changes
- interconnect driver fixes
- binder fix
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
interconnect: msm8916: Fix buswidth of pcnoc_s nodes
interconnect: Do not skip aggregation for disabled paths
/dev/mem: Add missing memory barriers for devmem_inode
binder: Don't use mmput() from shrinker function.
habanalabs: prevent possible out-of-bounds array access
fpga: dfl: fix bug in port reset handshake
fpga: dfl: pci: reduce the scope of variable 'ret'
habanalabs: set 4s timeout for message to device CPU
habanalabs: set clock gating per engine
habanalabs: block WREG_BULK packet on PDMA
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core into master
Pull driver core fix from Greg KH:
"A single driver core fix for 5.8-rc7. It resolves a problem found in
the previous fix for this code made in 5.8-rc6. Hopefully this is all
now cleared up, as this seems to be the last of the reported issues in
this area, and was tested on the problem hardware.
This patch has been in linux-next with no reported problems"
* tag 'driver-core-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
device property: Avoid NULL pointer dereference in device_get_next_child_node()
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