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authorJani Nikula <jani.nikula@intel.com>2023-05-04 13:35:08 +0300
committerJoonas Lahtinen <joonas.lahtinen@linux.intel.com>2023-05-11 14:11:59 +0300
commit79c901c93562bdf1c84ce6c1b744fbbe4389a6eb (patch)
tree5101a11a6a3f88ba2578f8a26a152ed3677a048e
parent0ff80028e2702c7c3d78b69705dc47c1ccba8c39 (diff)
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/Kconfig12
-rw-r--r--drivers/gpu/drm/i915/i915_pci.c6
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