<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  </head>
  <body>
    <pre class="moz-quote-pre" wrap="">Hi Sean,

<span style="white-space: normal">Tested-by: Yannick Fertre <a class="moz-txt-link-rfc2396E" href="mailto:yannick.fertre@foss.st.com"><yannick.fertre@foss.st.com></a> </span></pre>
    <pre class="moz-quote-pre" wrap="">Thanks for this patch,

Yannick
</pre>
    <p></p>
    <div class="moz-cite-prefix">Le 25/11/2024 à 14:49, Sean Nyekjaer a
      écrit :<br>
    </div>
    <blockquote type="cite"
      cite="mid:20241125-dsi-relax-v2-3-9113419f4a40@geanix.com">
      <pre class="moz-quote-pre" wrap="">When using the DSI interface via DSI2LVDS bridge, it seems a bit harsh
to reguire the requested and the actual px clock to be within
50Hz. A typical LVDS display requires the px clock to be within +-10%.

In case for HDMI .5% tolerance is required.

Signed-off-by: Sean Nyekjaer <a class="moz-txt-link-rfc2396E" href="mailto:sean@geanix.com"><sean@geanix.com></a>
---
 drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index b20123854c4ad7b3a2cc973a26fc10fd433e8d09..7b32abe0d4f582eea1fbbacad48c84199be3fa23 100644
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -484,8 +484,6 @@ dw_mipi_dsi_phy_get_timing(void *priv_data, unsigned int lane_mbps,
        return 0;
 }
 
-#define CLK_TOLERANCE_HZ 50
-
 static enum drm_mode_status
 dw_mipi_dsi_stm_mode_valid(void *priv_data,
                           const struct drm_display_mode *mode,
@@ -525,7 +523,7 @@ dw_mipi_dsi_stm_mode_valid(void *priv_data,
        }
 
        if (!(mode_flags & MIPI_DSI_MODE_VIDEO_BURST)) {
-               unsigned int px_clock_hz, target_px_clock_hz, lane_mbps;
+               unsigned int px_clock_hz, lane_mbps;
                int dsi_short_packet_size_px, hfp, hsync, hbp, delay_to_lp;
                struct dw_mipi_dsi_dphy_timing dphy_timing;
 
@@ -533,14 +531,14 @@ dw_mipi_dsi_stm_mode_valid(void *priv_data,
                pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf);
 
                px_clock_hz = DIV_ROUND_CLOSEST_ULL(1000ULL * pll_out_khz * lanes, bpp);
-               target_px_clock_hz = mode->clock * 1000;
                /*
                 * Filter modes according to the clock value, particularly useful for
                 * hdmi modes that require precise pixel clocks.
                 */
-               if (px_clock_hz < target_px_clock_hz - CLK_TOLERANCE_HZ ||
-                   px_clock_hz > target_px_clock_hz + CLK_TOLERANCE_HZ)
-                       return MODE_CLOCK_RANGE;
+
+               ret = drm_mode_validate_mode(mode, px_clock_hz);
+               if (ret)
+                       return ret;
 
                /* sync packets are codes as DSI short packets (4 bytes) */
                dsi_short_packet_size_px = DIV_ROUND_UP(4 * BITS_PER_BYTE, bpp);

</pre>
    </blockquote>
  </body>
</html>