Intel-XE Archive on lore.kernel.org
 help / color / mirror / Atom feed
* [Intel-xe] [PATCH] drm/xe: fix mcr semaphore locking for MTL
@ 2023-07-26 22:25 Daniele Ceraolo Spurio
  2023-07-26 23:12 ` [Intel-xe] ✓ CI.Patch_applied: success for " Patchwork
                   ` (7 more replies)
  0 siblings, 8 replies; 10+ messages in thread
From: Daniele Ceraolo Spurio @ 2023-07-26 22:25 UTC (permalink / raw)
  To: intel-xe; +Cc: Rodrigo Vivi

in commit 8604f978f45b ("drm/xe: Convert xe_mmio_wait32 to us so we can
stop using wait_for_us.") the mcr semaphore register read was
accidentally switched from waiting for the register to go to 1 to
waiting for the register to go to 0, so we need to flip it back.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_mcr.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_mcr.c b/drivers/gpu/drm/xe/xe_gt_mcr.c
index c56815af0686..9eb7a6a1348d 100644
--- a/drivers/gpu/drm/xe/xe_gt_mcr.c
+++ b/drivers/gpu/drm/xe/xe_gt_mcr.c
@@ -420,10 +420,11 @@ static void mcr_lock(struct xe_gt *gt)
 	/*
 	 * Starting with MTL we also need to grab a semaphore register
 	 * to synchronize with external agents (e.g., firmware) that now
-	 * shares the same steering control register.
+	 * shares the same steering control register. The semaphore is obtained
+	 * when a read to the relevant register returns 1.
 	 */
 	if (GRAPHICS_VERx100(xe) >= 1270)
-		ret = xe_mmio_wait32(gt, STEER_SEMAPHORE, 0, 0x1, 10, NULL,
+		ret = xe_mmio_wait32(gt, STEER_SEMAPHORE, 0x1, 0x1, 10, NULL,
 				     true);
 
 	drm_WARN_ON_ONCE(&xe->drm, ret == -ETIMEDOUT);
@@ -431,7 +432,7 @@ static void mcr_lock(struct xe_gt *gt)
 
 static void mcr_unlock(struct xe_gt *gt)
 {
-	/* Release hardware semaphore */
+	/* Release hardware semaphore - this is done by writing 1 to the register */
 	if (GRAPHICS_VERx100(gt_to_xe(gt)) >= 1270)
 		xe_mmio_write32(gt, STEER_SEMAPHORE, 0x1);
 
-- 
2.41.0


^ permalink raw reply related	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2023-07-27 13:55 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-07-26 22:25 [Intel-xe] [PATCH] drm/xe: fix mcr semaphore locking for MTL Daniele Ceraolo Spurio
2023-07-26 23:12 ` [Intel-xe] ✓ CI.Patch_applied: success for " Patchwork
2023-07-26 23:12 ` [Intel-xe] ✗ CI.checkpatch: warning " Patchwork
2023-07-26 23:13 ` [Intel-xe] ✓ CI.KUnit: success " Patchwork
2023-07-26 23:17 ` [Intel-xe] ✓ CI.Build: " Patchwork
2023-07-26 23:17 ` [Intel-xe] ✓ CI.Hooks: " Patchwork
2023-07-26 23:19 ` [Intel-xe] ✓ CI.checksparse: " Patchwork
2023-07-26 23:45 ` [Intel-xe] [PATCH] " Matt Roper
2023-07-27 13:55   ` Rodrigo Vivi
2023-07-26 23:53 ` [Intel-xe] ○ CI.BAT: info for " Patchwork

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox