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

From: Archit Taneja
Date: Wed Mar 14 2018 - 02:54:12 EST




On Saturday 10 March 2018 03:53 AM, Enric Balletbo i Serra wrote:
From: Douglas Anderson <dianders@xxxxxxxxxxxx>

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@xxxxxxxxxxxxxx>

Thanks,
Archit


Cc: StÃphane Marchesin <marcheu@xxxxxxxxxxxx>
Cc: åå ç <wzz@xxxxxxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxxxxx>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---

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 */