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[SRU,Focal:linux-intel-iotg-5.15,1/1] drm/i915/gt: Restrict the GT clock override to just Icelake

Message ID 20220509090411.38814-2-jianhui.lee@canonical.com
State New
Headers show
Series drm/i915/gt: Restrict the GT clock override to just Icelake | expand

Commit Message

Jian Hui Lee May 9, 2022, 9:04 a.m. UTC 
From: Chris Wilson <chris@chris-wilson.co.uk>

BugLink: https://bugs.launchpad.net/bugs/1945462

It appears that Elkhart Lake uses the same clock for CTX_TIMESTAMP as
CS_TIMESTAMP, leaving Icelake as the odd one out.

This patch was originated from
https://patchwork.freedesktop.org/patch/416618/?series=86446

Signed-off-by: Alex Hung <alex.hung@canonical.com>
Signed-off-by: Anthony Wong <anthony.wong@canonical.com>
Signed-off-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
(cherry picked from commit 939eb19a15aa195fb539d2aab115d811d74ffdf6 linux-intel-5.13)
Signed-off-by: Jian Hui Lee <jianhui.lee@canonical.com>
---
 drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c b/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
index 3513d6f90747..1c06bf3d63cd 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
@@ -159,6 +159,10 @@  void intel_gt_init_clock_frequency(struct intel_gt *gt)
 	if (gt->clock_frequency)
 		gt->clock_period_ns = intel_gt_clock_interval_to_ns(gt, 1);

+	/* Icelake appears to use another fixed frequency for CTX_TIMESTAMP */
+	if (IS_ICELAKE(gt->i915))
+		gt->clock_period_ns = NSEC_PER_SEC / 13750000;
+
 	GT_TRACE(gt,
 		 "Using clock frequency: %dkHz, period: %dns, wrap: %lldms\n",
 		 gt->clock_frequency / 1000,