Hi,

On 2017-11-27 22:30 -0500, Nick Bowler wrote:
> A note about the test setup: I had to remove the test equipment so I
> no longer have any information about the video mode from the sink side
> (like in the photos).  Thus, with the current setup, I am using the
> presense or absense of audio to determine whether the issue is present
> or not.
> 
> The test procedure is: boot up, start music, then hotplug the hdmi four
> times.  If sound is heard after all four connections, PASS; otherwise FAIL.
> 
>  - I retested on 4.15-rc1 to confirm that the issue is still present (it is).
> 
>  - I applied the functional revert from earlier on top of 4.15-rc1 and the
>    problem is fixed.
> 
>  - Returning to 4.15-rc1 and applying [Laurent Pinchart's] patch --
>    the issue is present again (no change in behaviour compared to
>    4.15-rc1).

Another data point... the following patch appears sufficient to restore
working behaviour.

Cheers,
  Nick

---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c 
b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index bf14214fa464..3118fbd8433d 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -1101,8 +1101,6 @@ static void dw_hdmi_phy_power_off(struct dw_hdmi *hdmi)
 static int dw_hdmi_phy_power_on(struct dw_hdmi *hdmi)
 {
        const struct dw_hdmi_phy_data *phy = hdmi->phy.data;
-       unsigned int i;
-       u8 val;
 
        if (phy->gen == 1) {
                dw_hdmi_phy_enable_powerdown(hdmi, false);
@@ -1116,21 +1114,6 @@ static int dw_hdmi_phy_power_on(struct dw_hdmi *hdmi)
        dw_hdmi_phy_gen2_txpwron(hdmi, 1);
        dw_hdmi_phy_gen2_pddq(hdmi, 0);
 
-       /* Wait for PHY PLL lock */
-       for (i = 0; i < 5; ++i) {
-               val = hdmi_readb(hdmi, HDMI_PHY_STAT0) & HDMI_PHY_TX_PHY_LOCK;
-               if (val)
-                       break;
-
-               usleep_range(1000, 2000);
-       }
-
-       if (!val) {
-               dev_err(hdmi->dev, "PHY PLL failed to lock\n");
-               return -ETIMEDOUT;
-       }
-
-       dev_dbg(hdmi->dev, "PHY PLL locked %u iterations\n", i);
        return 0;
 }
 
-- 
2.13.6
_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Reply via email to