The HSM clock needs to be running at 101% the pixel clock of the HDMI controller, however it's shared between the two HDMI controllers, which means that if the resolutions are different between the two HDMI controllers, and the lowest resolution is on the second (in enable order) controller, the first HDMI controller will end up with a smaller than expected clock rate.
Since we don't really need an exact frequency there, we can simply change the minimum rate we expect instead.
Reviewed-by: Dave Stevenson dave.stevenson@raspberrypi.com Tested-by: Chanwoo Choi cw00.choi@samsung.com Tested-by: Hoegeun Kwon hoegeun.kwon@samsung.com Tested-by: Stefan Wahren stefan.wahren@i2se.com Signed-off-by: Maxime Ripard maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_hdmi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 84273fe650d6..487c04de6b85 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -462,7 +462,7 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder) * pixel clock, but HSM ends up being the limiting factor. */ hsm_rate = max_t(unsigned long, 120000000, (pixel_rate / 100) * 101); - ret = clk_set_rate(vc4_hdmi->hsm_clock, hsm_rate); + ret = clk_set_min_rate(vc4_hdmi->hsm_clock, hsm_rate); if (ret) { DRM_ERROR("Failed to set HSM clock rate: %d\n", ret); return;