Hi Stephen On 7/26/2024 5:24 PM, Stephen Boyd wrote:
Quoting Abhinav Kumar (2024-07-25 15:03:19)diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c index a916b5f3b317..56ce5e4008f8 100644 --- a/drivers/gpu/drm/msm/dp/dp_panel.c +++ b/drivers/gpu/drm/msm/dp/dp_panel.c @@ -423,8 +424,10 @@ int dp_panel_init_panel_info(struct dp_panel *dp_panel) drm_mode->clock); drm_dbg_dp(panel->drm_dev, "bpp = %d\n", dp_panel->dp_mode.bpp); - dp_panel->dp_mode.bpp = max_t(u32, 18, - min_t(u32, dp_panel->dp_mode.bpp, 30)); + max_supported_bpp = dp_panel_get_mode_bpp(dp_panel, dp_panel->dp_mode.bpp, + dp_panel->dp_mode.drm_mode.clock); + dp_panel->dp_mode.bpp = max_t(u32, 18, max_supported_bpp);Is the max_t() usage still required once 'max_supported_bpp' is also a u32? Also, what is 18? Shouldn't that be some sort of define so we know what it represents? Or maybe none of that is required? From what I can tell, dp_panel_get_mode_bpp() calls dp_panel_get_supported_bpp() which will essentially clamp the bpp range between 18 and 30, unless dp_panel->dp_mode.bpp is between 30 and 18 but not divisible by 6, e.g. 29. Perhaps this patch can be included and the max_t above dropped. ---8<-- diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c index 07db8f37cd06..5cd7c138afd3 100644 --- a/drivers/gpu/drm/msm/dp/dp_panel.c +++ b/drivers/gpu/drm/msm/dp/dp_panel.c @@ -90,22 +90,22 @@ static int dp_panel_read_dpcd(struct dp_panel *dp_panel) static u32 dp_panel_get_supported_bpp(struct dp_panel *dp_panel, u32 mode_edid_bpp, u32 mode_pclk_khz) { - struct dp_link_info *link_info; + const struct dp_link_info *link_info; const u32 max_supported_bpp = 30, min_supported_bpp = 18; - u32 bpp = 0, data_rate_khz = 0; + u32 bpp, data_rate_khz; bpp = min_t(u32, mode_edid_bpp, max_supported_bpp); link_info = &dp_panel->link_info; data_rate_khz = link_info->num_lanes * link_info->rate * 8; - while (bpp > min_supported_bpp) { + do { if (mode_pclk_khz * bpp <= data_rate_khz) - break; + return bpp; bpp -= 6; - } + } while (bpp > min_supported_bpp); - return bpp; + return min_supported_bpp; }
Thanks for the feedback. Your change looks valid. We can use this and drop the max_t usage. Let me push this with your Suggested-by credits.
static int dp_panel_update_modes(struct drm_connector *connector,
