[PATCH 1/2] drm/bridge/lontium-lt9611uxc: fix waiting for EDID to become available

[Dmitry Baryshkov]

- Call wake_up() when EDID ready event is received to wake
  wait_event_interruptible_timeout()

- Increase waiting timeout, reading EDID can take longer than 100ms, so
  let's be on a safe side.

- Return NULL pointer from get_edid() callback rather than ERR_PTR()
  pointer, as DRM code does NULL checks rather than IS_ERR().

Signed-off-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org>
---
 drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c 
b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
index 0c98d27f84ac..b708700e182d 100644
--- a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
@@ -145,8 +145,10 @@ static irqreturn_t lt9611uxc_irq_thread_handler(int irq, 
void *dev_id)
 
        lt9611uxc_unlock(lt9611uxc);
 
-       if (irq_status & BIT(0))
+       if (irq_status & BIT(0)) {
                lt9611uxc->edid_read = !!(hpd_status & BIT(0));
+               wake_up_all(&lt9611uxc->wq);
+       }
 
        if (irq_status & BIT(1)) {
                if (lt9611uxc->connector.dev)
@@ -465,7 +467,7 @@ static enum drm_connector_status 
lt9611uxc_bridge_detect(struct drm_bridge *brid
 static int lt9611uxc_wait_for_edid(struct lt9611uxc *lt9611uxc)
 {
        return wait_event_interruptible_timeout(lt9611uxc->wq, 
lt9611uxc->edid_read,
-                       msecs_to_jiffies(100));
+                       msecs_to_jiffies(500));
 }
 
 static int lt9611uxc_get_edid_block(void *data, u8 *buf, unsigned int block, 
size_t len)
@@ -503,7 +505,10 @@ static struct edid *lt9611uxc_bridge_get_edid(struct 
drm_bridge *bridge,
        ret = lt9611uxc_wait_for_edid(lt9611uxc);
        if (ret < 0) {
                dev_err(lt9611uxc->dev, "wait for EDID failed: %d\n", ret);
-               return ERR_PTR(ret);
+               return NULL;
+       } else if (ret == 0) {
+               dev_err(lt9611uxc->dev, "wait for EDID timeout\n");
+               return NULL;
        }
 
        return drm_do_get_edid(connector, lt9611uxc_get_edid_block, lt9611uxc);
-- 
2.29.2

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel