Re: [PATCH v11 17/19] drm: bridge: analogix/dp: expand the look time for waiting AUX CH reply

Jingoo Han
2015-12-22T12:27:04Z

On Wednesday, December 16, 2015 12:58 PM, Yakir Yang wrote:
>
> After test on rockchiop platform, i found sometims driver would failed
> at reading EDID message. After debugging more, i found that it's okay
> to read_a byte from i2c, but it would failed at AUX transcation if we
> try to ready multi-bytes from i2c.
>
> Driver just can't received the AUX CH reply command, even no AUX error
> code. I may guess that the AUX wait time is not enough, so I try to
> expand the AUX wait time, and i do see this could fix the EDID read
> failed at rockchip platform.
>
> And I thought that expand the wait time won't hurt Exynos platform too
> much, cause Exynos didn't have this problem, then driver would received
> the reply command very soon, so no more additional wait time would bring
> to Exynos platform.
>
> Signed-off-by: Yakir Yang <ykk@rock-chips.com>
> ---
> Changes in v11: None
> Changes in v10: None
> Changes in v9: None
> Changes in v8: None
> Changes in v7: None
> Changes in v6: None
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
> drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> index c7e2959..dc376bd 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> @@ -482,7 +482,7 @@ int analogix_dp_start_aux_transaction(struct analogix_dp_device *dp)
> reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA);
> while (!(reg & RPLY_RECEIV)) {
> timeout_loop++;
> - if (DP_TIMEOUT_LOOP_COUNT < timeout_loop) {
> + if (DP_TIMEOUT_LOOP_COUNT * 10 < timeout_loop) {

No, I hate this coding.
analogix_dp_reg.c is the common code that can be shared by various SoCs.
Please, find another way.

Best regards,
Jingoo Han

> dev_err(dp->dev, "AUX CH command reply failed!\n");
> return -ETIMEDOUT;
> }
> --
> 1.9.1