On some servers with MGA G200_SE_A (rev 42), booting with Legacy BIOS,
the hardware hangs when using kdump and kexec into the kdump kernel.
This happens when the uncompress code tries to write "Decompressing Linux"
to the VGA Console.
It can be reproduced by writing to the VGA console (0xB8000) after
booting to graphic mode, it generates the following error:
kernel:NMI: PCI system error (SERR) for reason a0 on CPU 0.
kernel:Dazed and confused, but trying to continue
The root cause is the configuration of the MGA GCTL6 register
According to the GCTL6 register documentation:
bit 0 is gcgrmode:
0: Enables alpha mode, and the character generator addressing system is
activated.
1: Enables graphics mode, and the character addressing system is not
used.
bit 1 is chainodd even:
0: The A0 signal of the memory address bus is used during system memory
addressing.
1: Allows A0 to be replaced by either the A16 signal of the system
address (ifmemmapsl is ‘00’), or by the hpgoddev (MISC<5>, odd/even
page select) field, described on page 3-294).
bit 3-2 are memmapsl:
Memory map select bits 1 and 0. VGA.
These bits select where the video memory is mapped, as shown below:
00 => A0000h - BFFFFh
01 => A0000h - AFFFFh
10 => B0000h - B7FFFh
11 => B8000h - BFFFFh
bit 7-4 are reserved.
Current code set it to 0x05 => memmapsl to b01 => 0xa0000 (graphic mode)
But on x86, the VGA console is at 0xb8000 (text mode)
In arch/x86/boot/compressed/misc.c debug strings are written to 0xb8000
As the driver doesn't use this mapping at 0xa0000, it is safe to set it to
0xb8000 instead, to avoid kernel hang on G200_SE_A rev42, with kexec/kdump.
Thus changing the value 0x05 to 0x0d
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Lyude Paul <lyude@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220119102905.1194787-1-jfalempe@redhat.com
Move the base i915 buddy allocator code into drm
- Move i915_buddy.h to include/drm
- Move i915_buddy.c to drm root folder
- Rename "i915" string with "drm" string wherever applicable
- Rename "I915" string with "DRM" string wherever applicable
- Fix header file dependencies
- Fix alignment issues
- add Makefile support for drm buddy
- export functions and write kerneldoc description
- Remove i915 selftest config check condition as buddy selftest
will be moved to drm selftest folder
cleanup i915 buddy references in i915 driver module
and replace with drm buddy
v2:
- include header file in alphabetical order(Thomas)
- merged changes listed in the body section into a single patch
to keep the build intact(Christian, Jani)
v3:
- make drm buddy a separate module(Thomas, Christian)
v4:
- Fix build error reported by kernel test robot <lkp@intel.com>
- removed i915 buddy selftest from i915_mock_selftests.h to
avoid build error
- removed selftests/i915_buddy.c file as we create a new set of
buddy test cases in drm/selftests folder
v5:
- Fix merge conflict issue
v6:
- replace drm_buddy_mm structure name as drm_buddy(Thomas, Christian)
- replace drm_buddy_alloc() function name as drm_buddy_alloc_blocks()
(Thomas)
- replace drm_buddy_free() function name as drm_buddy_free_block()
(Thomas)
- export drm_buddy_free_block() function
- fix multiple instances of KMEM_CACHE() entry
v7:
- fix warnings reported by kernel test robot <lkp@intel.com>
- modify the license(Christian)
v8:
- fix warnings reported by kernel test robot <lkp@intel.com>
Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220118104504.2349-1-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>
It will connect to the mipi dsi host and find the corresponding
mipi dsi host node, but the node registered by the mipi dsi host
has not been loaded yet. of_find_mipi_dsi_host_by_node() returns -EINVAL
which causes the calling driver to fail.
If the anx7625 driver is loaded afterwards the driver requesting
the mipi dsi host will not notice this.
Better approach is to return -EPROBE_DEFER in such case.
Then when the anx7625 driver appears the driver requesting
the mipi dsi host will be probed again.
Signed-off-by: owen <qwt9588@gmail.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220117100949.9542-1-qwt9588@gamil.com
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Move DisplayPort functions into a separate module to reduce the size
of the KMS helpers. Select DRM_DP_HELPER for all users of the code. To
avoid naming conflicts, rename drm_dp_helper.c to drm_dp.c
This change can help to reduce the size of the kernel binary. Some
numbers from a x86-64 test build:
Before:
drm_kms_helper.ko: 447480 bytes
After:
drm_dp_helper.ko: 216632 bytes
drm_kms_helper.ko: 239424 bytes
For early-boot graphics, generic DRM drivers, such as simpledrm,
require DRM KMS helpers to be built into the kernel. Generic helper
functions for DisplayPort take up a significant portion of DRM KMS
helper library. These functions are not used by generic drivers and
can be loaded as a module.
v3:
* fix include statement in DRM selftests
v2:
* move DP helper code into dp/ (Jani)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Lyude Paul <lyude@redhat.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220114114535.29157-4-tzimmermann@suse.de
On a dual core group GPUs (such as T628) fragment shading can be
performed over all cores (because a fragment shader job doesn't
need coherency between threads), however vertex shading requires
to be run on the same core group as the tiler (which always lives
in core group 0).
As a first step to support T628 power on only the first core group
(so no jobs are scheduled on the second one). This makes T628 look
like every other Midgard GPU (and throws away up to half the cores).
With this patch panfrost is able to drive T628 (r1p0) GPU on some
armv8 SoCs (in particular BE-M1000). Without the patch rendering
is horribly broken (desktop is completely unusable) and eventually
the GPU locks up (it takes from a few seconds to a couple of
minutes).
Using the second core group requires support in Mesa (and an UABI
change): the userspace should
1) set PANFROST_JD_DOESNT_NEED_COHERENCY_ON_GPU flag to opt-in
to allowing the job to run across all cores.
2) set PANFROST_RUN_ON_SECOND_CORE_GROUP flag to allow compute
jobs to be run on the second core group (at the moment Mesa
does not advertise compute support on anything older than
Mali T760)
But there's little point adding such flags until someone (myself)
steps up to do the Mesa work.
Signed-off-by: Alexey Sheplyakov <asheplyakov@basealt.ru>
Signed-off-by: Vadim V. Vlasov <vadim.vlasov@elpitech.ru>
Tested-by: Alexey Sheplyakov <asheplyakov@basealt.ru>
Co-developed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220115160658.582646-1-asheplyakov@basealt.ru
When DRM_CHIPONE_ICN6211 is selected, and DRM_KMS_HELPER is not selected,
Kbuild gives the following warning:
WARNING: unmet direct dependencies detected for DRM_PANEL_BRIDGE
Depends on [n]: HAS_IOMEM [=y] && DRM_BRIDGE [=y] && DRM_KMS_HELPER [=n]
Selected by [y]:
- DRM_CHIPONE_ICN6211 [=y] && HAS_IOMEM [=y] && DRM [=y] && DRM_BRIDGE [=y] && OF [=y]
This is because DRM_CHIPONE_ICN6211 selects DRM_PANEL_BRIDGE
without depending on or selecting DRM_KMS_HELPER,
despite DRM_PANEL_BRIDGE depending on DRM_KMS_HELPER.
This unmet dependency bug was detected by Kismet,
a static analysis tool for Kconfig.
Fixes: ce517f1894 ("drm: bridge: Add Chipone ICN6211 MIPI-DSI to RGB bridge")
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Julian Braha <julianbraha@gmail.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220117052146.75811-1-julianbraha@gmail.com
Early versions of the legacy kernel driver included comprehensive
feature lists for every GPU, even though most of the enumerated features
only matter to userspace. For example, HW_FEATURE_INTERPIPE_REG_ALIASING
was a feature bit indicating that a GPU had "interpipe register
aliasing": arithmetic, load/store, and texture instruction all use
common general-purpose registers. GPUs without this feature bit have
dedicated load/store and texture "registers". Whether a GPU has this
feature or not is irrelevant to the kernel; it only matters in the
userspace compiler's register allocator. It's silly to enumerate it in
kernel space, and the information is understandably unused. To
underscore the point, this feature only makes sense in the context of
the Midgard instruction set. Bifrost never had dedicated load/store or
texture registers, so the feature bit was vacuously set for all Bifrost
hardware, even though this conveys no useful information.
To clean up the feature list, delete feature bits which could not
possibly matter to the kernel, leaving only those which do affect the
register-level operation of the chip.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220109170920.2921-2-alyssa.rosenzweig@collabora.com
