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Subject[PATCH v2] drm/bridge: Add 200ms delay to wait FW HPD status stable
Date
For the no-interrupt design (sink device is panel, polling HPD
status when chip power on), anx7625 FW has more than 200ms HPD
de-bounce time in FW, for the safety to get HPD status, driver
better to wait 200ms before HPD detection after OS resume back.

Signed-off-by: Xin Ji <xji@analogixsemi.com>
---
drivers/gpu/drm/bridge/analogix/anx7625.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 51abe42c639e..8f740154707d 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -1464,6 +1464,9 @@ static int _anx7625_hpd_polling(struct anx7625_data *ctx,
if (ctx->pdata.intp_irq)
return 0;

+ /* Delay 200ms for FW HPD de-bounce */
+ msleep(200);
+
ret = readx_poll_timeout(anx7625_read_hpd_status_p0,
ctx, val,
((val & HPD_STATUS) || (val < 0)),
--
2.25.1
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