| Message ID | 1432747308-345-1-git-send-email-jim.bride@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 27 May 2015, jim.bride@linux.intel.com wrote: > From: Jim Bride <jim.bride@linux.intel.com> > > According to the HSW b-spec we need to try clock divisors of 63 > and 72, each 3 or more times, when attempting DP AUX channel > communication on a server chipset. This actually wasn't happening > due to a short-circuit that only checked the DP_AUX_CH_CTL_DONE bit > in status rather than checking that the operation was done and > that DP_AUX_CH_CTL_TIME_OUT_ERROR was not set. > > [v2] Implemented alternate solution suggested by Jani Nikula. > > Signed-off-by: Jim Bride <jim.bride@linux.intel.com> Cc: stable@vger.kernel.org Reviewed-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/i915/intel_dp.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index 0edc305..7d1e024 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -893,10 +893,8 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, > continue; > } > if (status & DP_AUX_CH_CTL_DONE) > - break; > + goto done; > } > - if (status & DP_AUX_CH_CTL_DONE) > - break; > } > > if ((status & DP_AUX_CH_CTL_DONE) == 0) { > @@ -905,6 +903,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, > goto out; > } > > +done: > /* Check for timeout or receive error. > * Timeouts occur when the sink is not connected > */ > -- > 1.9.1 >
On Thu, 28 May 2015, Jani Nikula <jani.nikula@linux.intel.com> wrote: > On Wed, 27 May 2015, jim.bride@linux.intel.com wrote: >> From: Jim Bride <jim.bride@linux.intel.com> >> >> According to the HSW b-spec we need to try clock divisors of 63 >> and 72, each 3 or more times, when attempting DP AUX channel >> communication on a server chipset. This actually wasn't happening >> due to a short-circuit that only checked the DP_AUX_CH_CTL_DONE bit >> in status rather than checking that the operation was done and >> that DP_AUX_CH_CTL_TIME_OUT_ERROR was not set. >> >> [v2] Implemented alternate solution suggested by Jani Nikula. >> >> Signed-off-by: Jim Bride <jim.bride@linux.intel.com> > > Cc: stable@vger.kernel.org > Reviewed-by: Jani Nikula <jani.nikula@intel.com> ...and pushed to drm-intel-fixes, thanks for the patch. BR, Jani. > >> --- >> drivers/gpu/drm/i915/intel_dp.c | 5 ++--- >> 1 file changed, 2 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c >> index 0edc305..7d1e024 100644 >> --- a/drivers/gpu/drm/i915/intel_dp.c >> +++ b/drivers/gpu/drm/i915/intel_dp.c >> @@ -893,10 +893,8 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, >> continue; >> } >> if (status & DP_AUX_CH_CTL_DONE) >> - break; >> + goto done; >> } >> - if (status & DP_AUX_CH_CTL_DONE) >> - break; >> } >> >> if ((status & DP_AUX_CH_CTL_DONE) == 0) { >> @@ -905,6 +903,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, >> goto out; >> } >> >> +done: >> /* Check for timeout or receive error. >> * Timeouts occur when the sink is not connected >> */ >> -- >> 1.9.1 >> > > -- > Jani Nikula, Intel Open Source Technology Center
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 0edc305..7d1e024 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -893,10 +893,8 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, continue; } if (status & DP_AUX_CH_CTL_DONE) - break; + goto done; } - if (status & DP_AUX_CH_CTL_DONE) - break; } if ((status & DP_AUX_CH_CTL_DONE) == 0) { @@ -905,6 +903,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, goto out; } +done: /* Check for timeout or receive error. * Timeouts occur when the sink is not connected */