[PATCH v2 1/2] drm/msm/dsi: improve/fix dsc pclk calculation

From: Jonathan Marek
Date: Mon Oct 07 2024 - 01:06:12 EST


drm_mode_vrefresh() can introduce a large rounding error, avoid it.

Fixes: 7c9e4a554d4a ("drm/msm/dsi: Reduce pclk rate for compression")
Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
---
drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 185d7de0bf376..1205aa398e445 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -542,7 +542,7 @@ static unsigned long dsi_adjust_pclk_for_compression(const struct drm_display_mo

int new_htotal = mode->htotal - mode->hdisplay + new_hdisplay;

- return new_htotal * mode->vtotal * drm_mode_vrefresh(mode);
+ return mult_frac(mode->clock * 1000u, new_htotal, mode->htotal);
}

static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode,
--
2.45.1