Before the introduction of the wait_hpd_asserted() callback in
commit 841d742f09 ("drm/dp: Add wait_hpd_asserted() callback to struct
drm_dp_aux") the API between panel drivers and DP AUX bus drivers was
that it was up to the AUX bus driver to wait for HPD in the transfer()
function.
Now wait_hpd_asserted() has been added. The two panel drivers that are
DP AUX endpoints use it. See commit 2327b13d6c ("drm/panel-edp: Take
advantage of wait_hpd_asserted() in struct drm_dp_aux") and
commit 3b5765df37 ("drm/panel: atna33xc20: Take advantage of
wait_hpd_asserted() in struct drm_dp_aux"). We've implemented
wait_hpd_asserted() in the MSM DP driver as of commit e2969ee302
("drm/msm/dp: move of_dp_aux_populate_bus() to eDP probe()"). There is
no longer any reason for long wait in the AUX transfer() function.
Remove it.
NOTE: the wait_hpd_asserted() is listed as "optional". That means it's
optional for the DP AUX bus to implement. In the case of the MSM DP
driver we implement it so we can assume it will be called.
ALSO NOTE: the wait wasn't actually _hurting_ anything and wasn't even
causing long timeouts, but it's still nice to get rid of unneeded
code. Specificaly it's not truly needed because to handle other DP
drivers that can't power on as quickly (specifically parade-ps8640) we
already avoid DP AUX transfers for eDP panels that aren't powered
on. See commit 8df1ddb5bf ("drm/dp: Don't attempt AUX transfers when
eDP panels are not powered").
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/583130/
Link: https://lore.kernel.org/r/20240315143621.v2.3.I535606f6d4f7e3e5588bb75c55996f61980183cd@changeid
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
As documented in the description of the transfer() function of
"struct drm_dp_aux", the transfer() function can be called at any time
regardless of the state of the DP port. Specifically if the kernel has
the DP AUX character device enabled and userspace accesses
"/dev/drm_dp_auxN" directly then the AUX transfer function will be
called regardless of whether a DP device is connected.
For eDP panels we have a special rule where we wait (with a 5 second
timeout) for HPD to go high. This rule was important before all panels
drivers were converted to call wait_hpd_asserted() and actually can be
removed in a future commit.
For external DP devices we never checked for HPD. That means that
trying to access the DP AUX character device (AKA `hexdump -C
/dev/drm_dp_auxN`) would very, very slowly timeout. Specifically on my
system:
$ time hexdump -C /dev/drm_dp_aux0
hexdump: /dev/drm_dp_aux0: Connection timed out
real 0m8.200s
We want access to the drm_dp_auxN character device to fail faster than
8 seconds when no DP cable is plugged in.
Let's add a test to make transfers fail right away if a device isn't
plugged in. Rather than testing the HPD line directly, we have the
dp_display module tell us when AUX transfers should be enabled so we
can handle cases where HPD is signaled out of band like with Type C.
Fixes: c943b4948b ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/583127/
Link: https://lore.kernel.org/r/20240315143621.v2.1.I16aff881c9fe82b5e0fc06ca312da017aa7b5b3e@changeid
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Merge DisplayPort subnode API in order to allow DisplayPort driver to
configure the PHYs either to the DP or eDP mode, depending on hardware
configuration.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
The default highest_bank_bit of 15 didn't seem to cause issues so far
but downstream defines it to be 14. But similar to [0] leaving it on 14
(or 15 for that matter) causes some corruption issues with some
resolutions with DisplayPort, like 1920x1200.
So set it to 13 for now so that there's no screen corruption.
[0] commit 6a0dbcd20e ("drm/msm/a6xx: set highest_bank_bit to 13 for a610")
Fixes: b7616b5c69 ("drm/msm/adreno: Add A619 support")
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Patchwork: https://patchwork.freedesktop.org/patch/585215/
Signed-off-by: Rob Clark <robdclark@chromium.org>
Pull EFI fixes from Ard Biesheuvel:
- Fix logic that is supposed to prevent placement of the kernel image
below LOAD_PHYSICAL_ADDR
- Use the firmware stack in the EFI stub when running in mixed mode
- Clear BSS only once when using mixed mode
- Check efi.get_variable() function pointer for NULL before trying to
call it
* tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi: fix panic in kdump kernel
x86/efistub: Don't clear BSS twice in mixed mode
x86/efistub: Call mixed mode boot services on the firmware's stack
efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address
Pull x86 fixes from Thomas Gleixner:
- Ensure that the encryption mask at boot is properly propagated on
5-level page tables, otherwise the PGD entry is incorrectly set to
non-encrypted, which causes system crashes during boot.
- Undo the deferred 5-level page table setup as it cannot work with
memory encryption enabled.
- Prevent inconsistent XFD state on CPU hotplug, where the MSR is reset
to the default value but the cached variable is not, so subsequent
comparisons might yield the wrong result and as a consequence the
result prevents updating the MSR.
- Register the local APIC address only once in the MPPARSE enumeration
to prevent triggering the related WARN_ONs() in the APIC and topology
code.
- Handle the case where no APIC is found gracefully by registering a
fake APIC in the topology code. That makes all related topology
functions work correctly and does not affect the actual APIC driver
code at all.
- Don't evaluate logical IDs during early boot as the local APIC IDs
are not yet enumerated and the invoked function returns an error
code. Nothing requires the logical IDs before the final CPUID
enumeration takes place, which happens after the enumeration.
- Cure the fallout of the per CPU rework on UP which misplaced the
copying of boot_cpu_data to per CPU data so that the final update to
boot_cpu_data got lost which caused inconsistent state and boot
crashes.
- Use copy_from_kernel_nofault() in the kprobes setup as there is no
guarantee that the address can be safely accessed.
- Reorder struct members in struct saved_context to work around another
kmemleak false positive
- Remove the buggy code which tries to update the E820 kexec table for
setup_data as that is never passed to the kexec kernel.
- Update the resource control documentation to use the proper units.
- Fix a Kconfig warning observed with tinyconfig
* tag 'x86-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot/64: Move 5-level paging global variable assignments back
x86/boot/64: Apply encryption mask to 5-level pagetable update
x86/cpu: Add model number for another Intel Arrow Lake mobile processor
x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD
Documentation/x86: Document that resctrl bandwidth control units are MiB
x86/mpparse: Register APIC address only once
x86/topology: Handle the !APIC case gracefully
x86/topology: Don't evaluate logical IDs during early boot
x86/cpu: Ensure that CPU info updates are propagated on UP
kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address
x86/pm: Work around false positive kmemleak report in msr_build_context()
x86/kexec: Do not update E820 kexec table for setup_data
x86/config: Fix warning for 'make ARCH=x86_64 tinyconfig'
Pull scheduler doc clarification from Thomas Gleixner:
"A single update for the documentation of the base_slice_ns tunable to
clarify that any value which is less than the tick slice has no effect
because the scheduler tick is not guaranteed to happen within the set
time slice"
* tag 'sched-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/doc: Update documentation for base_slice_ns and CONFIG_HZ relation
Pull dma-mapping fixes from Christoph Hellwig:
"This has a set of swiotlb alignment fixes for sometimes very long
standing bugs from Will. We've been discussion them for a while and
they should be solid now"
* tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE
iommu/dma: Force swiotlb_max_mapping_size on an untrusted device
swiotlb: Fix alignment checks when both allocation and DMA masks are present
swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()
swiotlb: Enforce page alignment in swiotlb_alloc()
swiotlb: Fix double-allocation of slots due to broken alignment handling
Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.
Tested with QEMU and OVMF firmware.
Fixes: bad267f9e1 ("efi: verify that variable services are supported")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Clearing BSS should only be done once, at the very beginning.
efi_pe_entry() is the entrypoint from the firmware, which may not clear
BSS and so it is done explicitly. However, efi_pe_entry() is also used
as an entrypoint by the mixed mode startup code, in which case BSS will
already have been cleared, and doing it again at this point will corrupt
global variables holding the firmware's GDT/IDT and segment selectors.
So make the memset() conditional on whether the EFI stub is running in
native mode.
Fixes: b3810c5a2c ("x86/efistub: Clear decompressor BSS in native EFI entrypoint")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
