[PATCH 1/2] drm/i915/cdclk: Avoid spurious cdclk sanitization on PTL+

Ville Syrjala <[email protected]>
Newsgroups org.freedesktop.lists.intel-gfx,org.freedesktop.lists.intel-xe,org.kernel.vger.stable
Organization Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland
Message-ID <[email protected]>
From: Ville Syrjälä <[email protected]>

Apparently PTL+ no longer has the cd2x pipe select field in
CDCLK_CTL. Take that into account during CDCLK sanitization.

This currently triggers a spurious CDCLK sanitization during
driver load on PTL+ which will causes a visible glitch on all
active displays.

Cc: [email protected]
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/8550
Fixes: 3f9de66f8acb ("drm/i915/cdclk: Fix up CDCLK_FREQ_DECIMAL without a full PLL re-enable")
Signed-off-by: Ville Syrjälä <[email protected]>
---
 drivers/gpu/drm/i915/display/intel_cdclk.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index a53d88727177..9e5e15b0c4d1 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -2381,8 +2381,10 @@ static void bxt_sanitize_cdclk(struct intel_display *display)
 	 * dividers both syncing to an active pipe, or asynchronously
 	 * (PIPE_NONE).
 	 */
-	cdctl &= ~bxt_cdclk_cd2x_pipe_mask(display);
-	cdctl |= bxt_cdclk_cd2x_pipe(display, INVALID_PIPE);
+	if (DISPLAY_VER(display) < 30) {
+		cdctl &= ~bxt_cdclk_cd2x_pipe_mask(display);
+		cdctl |= bxt_cdclk_cd2x_pipe(display, INVALID_PIPE);
+	}
 
 	if (cdctl != expected) {
 		if (DISPLAY_VER(display) < 20) {
-- 
2.54.0
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