On 02/12/2022 22:49, Rodrigo Vivi wrote:
On Fri, Dec 02, 2022 at 02:35:28PM -0800, Matt Roper wrote:
When determining whether the platform has a hardware-level steering
semaphore (i.e., MTL and beyond), we need to use GRAPHICS_VER_FULL() to
compare the full version rather than just the major version number
returned by GRAPHICS_VER().
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Fixes: 3100240bf846 ("drm/i915/mtl: Add hardware-level lock for steering")
Cc: Balasubramani Vivekanandan <balasubramani.vivekanandan@xxxxxxxxx>
Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_gt_mcr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c
index 087e4ac5b68d..41a237509dcf 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c
@@ -367,7 +367,7 @@ void intel_gt_mcr_lock(struct intel_gt *gt, unsigned long *flags)
* driver threads, but also with hardware/firmware agents. A dedicated
* locking register is used.
*/
- if (GRAPHICS_VER(gt->i915) >= IP_VER(12, 70))
+ if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
Ouch, tricky class of bugs... Anyone has an idea how to maybe coerce the compiler into spotting them for us, cheaply?
This one is undefined behaviour I think so not good:
-#define IP_VER(ver, rel) ((ver) << 8 | (rel))
+typedef void * i915_full_ver_t;
+
+#define IP_VER(ver, rel) (i915_full_ver_t)(unsigned long)((ver) << 8 | (rel))
Regards,
Tvrtko
err = wait_for(intel_uncore_read_fw(gt->uncore,
MTL_STEER_SEMAPHORE) == 0x1, 100);
@@ -407,7 +407,7 @@ void intel_gt_mcr_unlock(struct intel_gt *gt, unsigned long flags)
{
spin_unlock_irqrestore(>->mcr_lock, flags);
- if (GRAPHICS_VER(gt->i915) >= IP_VER(12, 70))
+ if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
intel_uncore_write_fw(gt->uncore, MTL_STEER_SEMAPHORE, 0x1);
}
--
2.38.1
