| Message ID | 1662671917-17194-3-git-send-email-quic_khsieh@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | cleared DP_DOWNSPREAD_CTRL register | expand |
On Fri, 9 Sept 2022 at 00:18, Kuogee Hsieh <quic_khsieh@quicinc.com> wrote: > > 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 v4: > -- split into two patches > > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> > --- > drivers/gpu/drm/msm/dp/dp_link.c | 21 ++++++++++++--------- > 1 file changed, 12 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c > index 36f0af0..7b5ecf5 100644 > --- a/drivers/gpu/drm/msm/dp/dp_link.c > +++ b/drivers/gpu/drm/msm/dp/dp_link.c > @@ -49,23 +49,26 @@ static int dp_aux_link_power_up(struct drm_dp_aux *aux, > struct dp_link_info *link) > { > u8 value; > - int err; > + ssize_t len; > + int i; > > if (link->revision < 0x11) > return 0; > > - err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); > - if (err < 0) > - return err; > + len = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); > + if (len < 0) > + return len; This is a separate patch. > > value &= ~DP_SET_POWER_MASK; > value |= DP_SET_POWER_D0; > > - err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); > - if (err < 0) > - return err; > - > - 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; > } > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c index 36f0af0..7b5ecf5 100644 --- a/drivers/gpu/drm/msm/dp/dp_link.c +++ b/drivers/gpu/drm/msm/dp/dp_link.c @@ -49,23 +49,26 @@ static int dp_aux_link_power_up(struct drm_dp_aux *aux, struct dp_link_info *link) { u8 value; - int err; + ssize_t len; + int i; if (link->revision < 0x11) return 0; - err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); - if (err < 0) - return err; + len = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); + if (len < 0) + return len; value &= ~DP_SET_POWER_MASK; value |= DP_SET_POWER_D0; - err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); - if (err < 0) - return err; - - 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; }
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 v4: -- split into two patches Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> --- drivers/gpu/drm/msm/dp/dp_link.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)