[PATCH AUTOSEL 6.18] drm/xe: Fix bug in idledly unit conversion

[Sasha Levin <sashal@kernel.org>]

From: Vinay Belgaumkar <vinay.belgaumkar@intel.com>

[ Upstream commit 7596459f3c93d8d45a1bf12d4d7526b50c15baa2 ]

We only need to convert to picosecond units before writing to RING_IDLEDLY.

Fixes: 7c53ff050ba8 ("drm/xe: Apply Wa_16023105232")
Cc: Tangudu Tilak Tirumalesh <tilak.tirumalesh.tangudu@intel.com>
Acked-by: Tangudu Tilak Tirumalesh <tilak.tirumalesh.tangudu@intel.com>
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Link: https://patch.msgid.link/20260401012710.4165547-1-vinay.belgaumkar@intel.com
(cherry picked from commit 13743bd628bc9d9a0e2fe53488b2891aedf7cc74)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

Error: Failed to generate final synthesis

 drivers/gpu/drm/xe/xe_hw_engine.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
index 1cf623b4a5bcc..d8f16e25b817d 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine.c
+++ b/drivers/gpu/drm/xe/xe_hw_engine.c
@@ -587,9 +587,8 @@ static void adjust_idledly(struct xe_hw_engine *hwe)
 		maxcnt *= maxcnt_units_ns;
 
 		if (xe_gt_WARN_ON(gt, idledly >= maxcnt || inhibit_switch)) {
-			idledly = DIV_ROUND_CLOSEST(((maxcnt - 1) * maxcnt_units_ns),
+			idledly = DIV_ROUND_CLOSEST(((maxcnt - 1) * 1000),
 						    idledly_units_ps);
-			idledly = DIV_ROUND_CLOSEST(idledly, 1000);
 			xe_mmio_write32(&gt->mmio, RING_IDLEDLY(hwe->mmio_base), idledly);
 		}
 	}
-- 
2.53.0