tjh.dev
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1443962
3
927
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
It incorrectly claimed a resource isn't CPU visible if it's located at
the very end of CPU visible VRAM.
Fixes: a6ff969fe9cb ("drm/amdgpu: fix visible VRAM handling during faults")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3343
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reported-and-Tested-by: Jeremy Day <jsday@noreason.ca>
Signed-off-by: Michel Dänzer <mdaenzer@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
CC: stable@vger.kernel.org
We don't get the right offset in that case. The GPU has
an unused 4K area of the register BAR space into which you can
remap registers. We remap the HDP flush registers into this
space to allow userspace (CPU or GPU) to flush the HDP when it
updates VRAM. However, on systems with >4K pages, we end up
exposing PAGE_SIZE of MMIO space.
Fixes: d8e408a82704 ("drm/amdkfd: Expose HDP registers to user space")
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
This reverts commit c37ce764cd492f044dcdbb39616298f02b0dbc7f.
RCCL library is currently not treating spatial partitions differently,
hence this change is causing issues. Revert temporarily till RCCL
implementation is ready for spatial partitions.
Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Jonathan Kim <jonathan.kim@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Limit the workaround introduced by commit 31729e8c21ec ("drm/amd/pm: fixes
a random hang in S4 for SMU v13.0.4/11") to only run in the s4 path.
Cc: Tim Huang <Tim.Huang@amd.com>
Fixes: 31729e8c21ec ("drm/amd/pm: fixes a random hang in S4 for SMU v13.0.4/11")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3351
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
Some older MST hubs do not report DPCD registers according to
specification.
[How]
This change re-applies commit c53655545141 ("drm/amd/display: dsc mst
re-compute pbn for changes on hub").
With an additional check for these older MST devices.
Reviewed-by: Swapnil Patel <swapnil.patel@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Agustin Gutierrez <agustin.gutierrez@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
Idle optimizations are blocked if there's more than one eDP connector
on the board - blocking S0i3 and IPS2 for static screen.
[How]
Fix the checks to correctly detect number of active eDP.
Also restrict the eDP support to panels that have correct feature
support.
Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
This fixes a bug introduced by commit c53655545141 ("drm/amd/display: dsc
mst re-compute pbn for changes on hub").
The change caused light-up issues with a second display that required
DSC on some MST docks.
[How]
Use Virtual DPCD for DSC caps in MST case.
[Limitations]
This change only affects MST DSC devices that follow specifications
additional changes are required to check for old MST DSC devices such as
ones which do not check for Virtual DPCD registers.
Reviewed-by: Swapnil Patel <swapnil.patel@amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Agustin Gutierrez <agustin.gutierrez@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
Underflow occurs when running Netflix in a 4k144 eDP + 4k60 HDMI FRL
setup. It is caused by latency varying based on the DCFCLK/FCLK state.
[How]
Enable urgent latency adjustment and match the reference to existing
ASIC that also see increased latency at low FCLK.
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Nicholas Susanto <nicholas.susanto@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
epoll can call out to vfs_poll() with a file pointer that may race with
the last 'fput()'. That would make f_count go down to zero, and while
the ep->mtx locking means that the resulting file pointer tear-down will
be blocked until the poll returns, it means that f_count is already
dead, and any use of it won't actually get a reference to the file any
more: it's dead regardless.
Make sure we have a valid ref on the file pointer before we call down to
vfs_poll() from the epoll routines.
Link: https://lore.kernel.org/lkml/0000000000002d631f0615918f1e@google.com/
Reported-by: syzbot+045b454ab35fd82a35fb@syzkaller.appspotmail.com
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull EDAC fixes from Borislav Petkov:
- Fix error logging and check user-supplied data when injecting an
error in the versal EDAC driver
* tag 'edac_urgent_for_v6.9_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
EDAC/versal: Do not log total error counts
EDAC/versal: Check user-supplied data before injecting an error
EDAC/versal: Do not register for NOC errors
Pull powerpc fixes from Michael Ellerman:
- Fix incorrect delay handling in the plpks (keystore) code
- Fix a panic when an LPAR boots with a frozen PE
Thanks to Andrew Donnellan, Gaurav Batra, Nageswara R Sastry, and Nayna
Jain.
* tag 'powerpc-6.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/pseries/iommu: LPAR panics during boot up with a frozen PE
powerpc/pseries: make max polling consistent for longer H_CALLs
When logging errors, the driver currently logs the total error count.
However, it should log the current error only. Fix it.
[ bp: Rewrite text. ]
Fixes: 6f15b178cd63 ("EDAC/versal: Add a Xilinx Versal memory controller driver")
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240425121942.26378-4-shubhrajyoti.datta@amd.com
Pull misc x86 fixes from Ingo Molnar:
- Remove the broken vsyscall emulation code from
the page fault code
- Fix kexec crash triggered by certain SEV RMP
table layouts
- Fix unchecked MSR access error when disabling
the x2APIC via iommu=off
* tag 'x86-urgent-2024-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Remove broken vsyscall emulation code from the page fault code
x86/apic: Don't access the APIC when disabling x2APIC
x86/sev: Add callback to apply RMP table fixups for kexec
x86/e820: Add a new e820 table update helper
At the time of LPAR boot up, partition firmware provides Open Firmware
property ibm,dma-window for the PE. This property is provided on the PCI
bus the PE is attached to.
There are execptions where the partition firmware might not provide this
property for the PE at the time of LPAR boot up. One of the scenario is
where the firmware has frozen the PE due to some error condition. This
PE is frozen for 24 hours or unless the whole system is reinitialized.
Within this time frame, if the LPAR is booted, the frozen PE will be
presented to the LPAR but ibm,dma-window property could be missing.
Today, under these circumstances, the LPAR oopses with NULL pointer
dereference, when configuring the PCI bus the PE is attached to.
BUG: Kernel NULL pointer dereference on read at 0x000000c8
Faulting instruction address: 0xc0000000001024c0
Oops: Kernel access of bad area, sig: 7 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
Modules linked in:
Supported: Yes
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.4.0-150600.9-default #1
Hardware name: IBM,9043-MRX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_023) hv:phyp pSeries
NIP: c0000000001024c0 LR: c0000000001024b0 CTR: c000000000102450
REGS: c0000000037db5c0 TRAP: 0300 Not tainted (6.4.0-150600.9-default)
MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 28000822 XER: 00000000
CFAR: c00000000010254c DAR: 00000000000000c8 DSISR: 00080000 IRQMASK: 0
...
NIP [c0000000001024c0] pci_dma_bus_setup_pSeriesLP+0x70/0x2a0
LR [c0000000001024b0] pci_dma_bus_setup_pSeriesLP+0x60/0x2a0
Call Trace:
pci_dma_bus_setup_pSeriesLP+0x60/0x2a0 (unreliable)
pcibios_setup_bus_self+0x1c0/0x370
__of_scan_bus+0x2f8/0x330
pcibios_scan_phb+0x280/0x3d0
pcibios_init+0x88/0x12c
do_one_initcall+0x60/0x320
kernel_init_freeable+0x344/0x3e4
kernel_init+0x34/0x1d0
ret_from_kernel_user_thread+0x14/0x1c
Fixes: b1fc44eaa9ba ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window")
Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240422205141.10662-1-gbatra@linux.ibm.com
README