diff mbox series

[SRU,I/raspi,10/10] drm/vc4: Increase the core clock to a minimum of 500MHz

Message ID 20211018155848.334053-11-juergh@canonical.com
State New
Headers show
Series HDMI output freezes under current/proposed impish kernels (LP: #1946368) | expand

Commit Message

Juerg Haefliger Oct. 18, 2021, 3:58 p.m. UTC 
From: Maxime Ripard <maxime@cerno.tech>

BugLink: https://bugs.launchpad.net/bugs/1946368

The core clock needs to be raised temporarily during a modeset to
500MHz. However, the HVS core clock requirement might be higher than
500MHz. This rate will be enforced at the end of the mode setting,
meaning that might might end up with a core clock rate lower than
planned on the first mode set.

Use the maximum value of 500MHz and the HVS core clock rate for our
temporary boost to fix this issue.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

(forward ported from commit 0a7c2180876d9c7748e055091be21efb959934e2 rpi-5.10.y)
[juergh: new_hvs_state -> hvs_state.]
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
---
 drivers/gpu/drm/vc4/vc4_kms.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
index 10990d7cc285..fb2465964d46 100644
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -348,11 +348,17 @@  vc4_atomic_complete_commit(struct drm_atomic_state *state)
 	}
 
 	if (vc4->hvs && vc4->hvs->hvs5) {
+		unsigned long core_rate = max_t(unsigned long,
+						500000000,
+						hvs_state->core_clock_rate);
+
+		drm_dbg(dev, "Raising the core clock at %lu Hz\n", core_rate);
+
 		/*
 		 * Do a temporary request on the core clock during the
 		 * modeset.
 		 */
-		core_req = clk_request_start(hvs->core_clk, 500000000);
+		core_req = clk_request_start(hvs->core_clk, core_rate);
 
 		/*
 		 * And remove the previous one based on the HVS