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| author | Jani Nikula <jani.nikula@intel.com> | 2023-05-04 12:35:08 +0200 |
|---|---|---|
| committer | Joonas Lahtinen <joonas.lahtinen@linux.intel.com> | 2023-05-11 13:11:59 +0200 |
| commit | 79c901c93562bdf1c84ce6c1b744fbbe4389a6eb (patch) | |
| tree | 5101a11a6a3f88ba2578f8a26a152ed3677a048e | |
| parent | drm/i915/dp: prevent potential div-by-zero (diff) | |
| download | linux-79c901c93562bdf1c84ce6c1b744fbbe4389a6eb.tar.xz linux-79c901c93562bdf1c84ce6c1b744fbbe4389a6eb.zip | |
drm/i915: taint kernel when force probing unsupported devices
For development and testing purposes, the i915.force_probe module
parameter and DRM_I915_FORCE_PROBE kconfig option allow probing of
devices that aren't supported by the driver.
The i915.force_probe module parameter is "unsafe" and setting it taints
the kernel. However, using the kconfig option does not.
Always taint the kernel when force probing a device that is not
supported.
v2: Drop "depends on EXPERT" to avoid build breakage (kernel test robot)
Fixes: 7ef5ef5cdead ("drm/i915: add force_probe module parameter to replace alpha_support")
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230504103508.1818540-1-jani.nikula@intel.com
(cherry picked from commit 3312bb4ad09ca6423bd4a5b15a94588a8962fb8e)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/i915_pci.c | 6 |
2 files changed, 13 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig index 06a0ca157e89..e4f4d2e3fdfe 100644 --- a/drivers/gpu/drm/i915/Kconfig +++ b/drivers/gpu/drm/i915/Kconfig @@ -62,10 +62,11 @@ config DRM_I915_FORCE_PROBE This is the default value for the i915.force_probe module parameter. Using the module parameter overrides this option. - Force probe the i915 for Intel graphics devices that are - recognized but not properly supported by this kernel version. It is - recommended to upgrade to a kernel version with proper support as soon - as it is available. + Force probe the i915 driver for Intel graphics devices that are + recognized but not properly supported by this kernel version. Force + probing an unsupported device taints the kernel. It is recommended to + upgrade to a kernel version with proper support as soon as it is + available. It can also be used to block the probe of recognized and fully supported devices. @@ -75,7 +76,8 @@ config DRM_I915_FORCE_PROBE Use "<pci-id>[,<pci-id>,...]" to force probe the i915 for listed devices. For example, "4500" or "4500,4571". - Use "*" to force probe the driver for all known devices. + Use "*" to force probe the driver for all known devices. Not + recommended. Use "!" right before the ID to block the probe of the device. For example, "4500,!4571" forces the probe of 4500 and blocks the probe of diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c index 2a012da8ccfa..edcfb5fe20b2 100644 --- a/drivers/gpu/drm/i915/i915_pci.c +++ b/drivers/gpu/drm/i915/i915_pci.c @@ -1344,6 +1344,12 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent) return -ENODEV; } + if (intel_info->require_force_probe) { + dev_info(&pdev->dev, "Force probing unsupported Device ID %04x, tainting kernel\n", + pdev->device); + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + } + /* Only bind to function 0 of the device. Early generations * used function 1 as a placeholder for multi-head. This causes * us confusion instead, especially on the systems where both |