Bring sink out of D3 (power down) mode into D0 (normal operation) mode
by setting DP_SET_POWER_D0 bit to DP_SET_POWER dpcd register. This
patch will retry 3 times if written to DP_SET_POWER register failed.
Changes in v5:
-- split into two patches
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/502536/
Link: https://lore.kernel.org/r/1662999830-13916-4-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
{
u8 value;
ssize_t len;
+ int i;
if (link->revision < 0x11)
return 0;
value &= ~DP_SET_POWER_MASK;
value |= DP_SET_POWER_D0;
- len = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
- if (len < 0)
- return len;
-
- usleep_range(1000, 2000);
+ /* retry for 1ms to give the sink time to wake up */
+ for (i = 0; i < 3; i++) {
+ len = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
+ usleep_range(1000, 2000);
+ if (len == 1)
+ break;
+ }
return 0;
}