Re: [PATCH v5 26/36] drm/bridge: analogix_dp: Properly disable aux chan retries on rockchip

Archit Taneja
2018-03-14T06:53:49Z

On Saturday 10 March 2018 03:53 AM, Enric Balletbo i Serra wrote:
> From: Douglas Anderson <dianders@chromium.org>
>
> The comments in analogix_dp_init_aux() claim that we're disabling aux
> channel retries, but then right below it for Rockchip it sets them to
> 3. If we actually need 3 retries for Rockchip then we could adjust
> the comment, but it seems more likely that we want the same retry
> behavior across all platforms.

Reviewed-by: Archit Taneja <architt@codeaurora.org>

Thanks,
Archit

>
> Cc: Stéphane Marchesin <marcheu@chromium.org>
> Cc: 征增 王 <wzz@rock-chips.com>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>
> drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> index 58e8a28e99aa..a5f2763d72e4 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> @@ -481,15 +481,16 @@ void analogix_dp_init_aux(struct analogix_dp_device *dp)
>
> analogix_dp_reset_aux(dp);
>
> - /* Disable AUX transaction H/W retry */
> + /* AUX_BIT_PERIOD_EXPECTED_DELAY doesn't apply to Rockchip IP */
> if (dp->plat_data && is_rockchip(dp->plat_data->dev_type))
> - reg = AUX_BIT_PERIOD_EXPECTED_DELAY(0) |
> - AUX_HW_RETRY_COUNT_SEL(3) |
> - AUX_HW_RETRY_INTERVAL_600_MICROSECONDS;
> + reg = 0;
> else
> - reg = AUX_BIT_PERIOD_EXPECTED_DELAY(3) |
> - AUX_HW_RETRY_COUNT_SEL(0) |
> - AUX_HW_RETRY_INTERVAL_600_MICROSECONDS;
> + reg = AUX_BIT_PERIOD_EXPECTED_DELAY(3);
> +
> + /* Disable AUX transaction H/W retry */
> + reg |= AUX_HW_RETRY_COUNT_SEL(0) |
> + AUX_HW_RETRY_INTERVAL_600_MICROSECONDS;
> +
> writel(reg, dp->reg_base + ANALOGIX_DP_AUX_HW_RETRY_CTL);
>
> /* Receive AUX Channel DEFER commands equal to DEFFER_COUNT*64 */
>