Michal Wajdeczko 459777724d drm/xe/vf: Don't try to trigger a full GT reset if VF
VFs don't have access to the GDRST(0x941c) register that driver
uses to reset a GT. Attempt to trigger a reset using debugfs:

 $ cat /sys/kernel/debug/dri/0000:00:02.1/gt0/force_reset

or due to a hang condition detected by the driver leads to:

 [ ] xe 0000:00:02.1: [drm] GT0: trying reset from force_reset [xe]
 [ ] xe 0000:00:02.1: [drm] GT0: reset queued
 [ ] xe 0000:00:02.1: [drm] GT0: reset started
 [ ] ------------[ cut here ]------------
 [ ] xe 0000:00:02.1: [drm] GT0: VF is trying to write 0x1 to an inaccessible register 0x941c+0x0
 [ ] WARNING: CPU: 3 PID: 3069 at drivers/gpu/drm/xe/xe_gt_sriov_vf.c:996 xe_gt_sriov_vf_write32+0xc6/0x580 [xe]
 [ ] RIP: 0010:xe_gt_sriov_vf_write32+0xc6/0x580 [xe]
 [ ] Call Trace:
 [ ]  <TASK>
 [ ]  ? show_regs+0x6c/0x80
 [ ]  ? __warn+0x93/0x1c0
 [ ]  ? xe_gt_sriov_vf_write32+0xc6/0x580 [xe]
 [ ]  ? report_bug+0x182/0x1b0
 [ ]  ? handle_bug+0x6e/0xb0
 [ ]  ? exc_invalid_op+0x18/0x80
 [ ]  ? asm_exc_invalid_op+0x1b/0x20
 [ ]  ? xe_gt_sriov_vf_write32+0xc6/0x580 [xe]
 [ ]  ? xe_gt_sriov_vf_write32+0xc6/0x580 [xe]
 [ ]  ? xe_gt_tlb_invalidation_reset+0xef/0x110 [xe]
 [ ]  ? __mutex_unlock_slowpath+0x41/0x2e0
 [ ]  xe_mmio_write32+0x64/0x150 [xe]
 [ ]  do_gt_reset+0x2f/0xa0 [xe]
 [ ]  gt_reset_worker+0x14e/0x1e0 [xe]
 [ ]  process_one_work+0x21c/0x740
 [ ]  worker_thread+0x1db/0x3c0

Fix that by sending H2G VF_RESET(0x5507) action instead.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4078
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250131182502.852-1-michal.wajdeczko@intel.com
2025-02-04 15:31:45 +01:00
2025-01-23 14:42:21 +01:00
2025-01-23 14:42:21 +01:00
2025-01-23 14:42:21 +01:00
2024-09-01 20:43:24 -07:00
2025-01-23 14:42:21 +01:00
2025-01-23 14:42:21 +01:00
2022-09-28 09:02:20 +02:00
2025-01-19 15:51:45 -08:00
2024-03-18 03:36:32 -06:00

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.
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