| Message ID | 1485509961-9010-3-git-send-email-imre.deak@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Regards Shashank On 1/27/2017 3:09 PM, Imre Deak wrote: > During system resume time initialization the HPD level on LSPCON ports > can stay low for an extended amount of time, leading to failed AUX > transfers and LSPCON initialization. Fix this by waiting for HPD to get > asserted. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99178 > Cc: Shashank Sharma <shashank.sharma@intel.com> > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: <stable@vger.kernel.org> # v4.9+ > Signed-off-by: Imre Deak <imre.deak@intel.com> > --- > drivers/gpu/drm/i915/intel_dp.c | 4 ++-- > drivers/gpu/drm/i915/intel_drv.h | 2 ++ > drivers/gpu/drm/i915/intel_lspcon.c | 5 ++++- > 3 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index e0f9b9e..a7785ce 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -4400,8 +4400,8 @@ static bool bxt_digital_port_connected(struct drm_i915_private *dev_priv, > * > * Return %true if @port is connected, %false otherwise. > */ > -static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > - struct intel_digital_port *port) > +bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > + struct intel_digital_port *port) > { > if (HAS_PCH_IBX(dev_priv)) > return ibx_digital_port_connected(dev_priv, port); > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index b71fece..b9cde11 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -1489,6 +1489,8 @@ bool __intel_dp_read_desc(struct intel_dp *intel_dp, > bool intel_dp_read_desc(struct intel_dp *intel_dp); > int intel_dp_link_required(int pixel_clock, int bpp); > int intel_dp_max_data_rate(int max_link_clock, int max_lanes); > +bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > + struct intel_digital_port *port); > > /* intel_dp_aux_backlight.c */ > int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector); > diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c > index f6d4e69..c300647 100644 > --- a/drivers/gpu/drm/i915/intel_lspcon.c > +++ b/drivers/gpu/drm/i915/intel_lspcon.c > @@ -158,6 +158,8 @@ static bool lspcon_probe(struct intel_lspcon *lspcon) > static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) > { > struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon); > + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); > + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); > unsigned long start = jiffies; > > if (!lspcon->desc_valid) > @@ -173,7 +175,8 @@ static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) > if (!__intel_dp_read_desc(intel_dp, &desc)) > return; > > - if (!memcmp(&intel_dp->desc, &desc, sizeof(desc))) { > + if (intel_digital_port_connected(dev_priv, dig_port) && when in PCON mode, live_status is always up for LSPCON port, so this check will be always true, isn't it ? - Shashank > + !memcmp(&intel_dp->desc, &desc, sizeof(desc))) { > DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n", > jiffies_to_msecs(jiffies - start)); > return;
On Sat, Jan 28, 2017 at 10:32:03AM +0530, Sharma, Shashank wrote: > Regards > > Shashank > > > On 1/27/2017 3:09 PM, Imre Deak wrote: > >During system resume time initialization the HPD level on LSPCON ports > >can stay low for an extended amount of time, leading to failed AUX > >transfers and LSPCON initialization. Fix this by waiting for HPD to get > >asserted. > > > >Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99178 > >Cc: Shashank Sharma <shashank.sharma@intel.com> > >Cc: Jani Nikula <jani.nikula@linux.intel.com> > >Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > >Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > >Cc: <stable@vger.kernel.org> # v4.9+ > >Signed-off-by: Imre Deak <imre.deak@intel.com> > >--- > > drivers/gpu/drm/i915/intel_dp.c | 4 ++-- > > drivers/gpu/drm/i915/intel_drv.h | 2 ++ > > drivers/gpu/drm/i915/intel_lspcon.c | 5 ++++- > > 3 files changed, 8 insertions(+), 3 deletions(-) > > > >diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > >index e0f9b9e..a7785ce 100644 > >--- a/drivers/gpu/drm/i915/intel_dp.c > >+++ b/drivers/gpu/drm/i915/intel_dp.c > >@@ -4400,8 +4400,8 @@ static bool bxt_digital_port_connected(struct drm_i915_private *dev_priv, > > * > > * Return %true if @port is connected, %false otherwise. > > */ > >-static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > >- struct intel_digital_port *port) > >+bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > >+ struct intel_digital_port *port) > > { > > if (HAS_PCH_IBX(dev_priv)) > > return ibx_digital_port_connected(dev_priv, port); > >diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > >index b71fece..b9cde11 100644 > >--- a/drivers/gpu/drm/i915/intel_drv.h > >+++ b/drivers/gpu/drm/i915/intel_drv.h > >@@ -1489,6 +1489,8 @@ bool __intel_dp_read_desc(struct intel_dp *intel_dp, > > bool intel_dp_read_desc(struct intel_dp *intel_dp); > > int intel_dp_link_required(int pixel_clock, int bpp); > > int intel_dp_max_data_rate(int max_link_clock, int max_lanes); > >+bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > >+ struct intel_digital_port *port); > > /* intel_dp_aux_backlight.c */ > > int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector); > >diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c > >index f6d4e69..c300647 100644 > >--- a/drivers/gpu/drm/i915/intel_lspcon.c > >+++ b/drivers/gpu/drm/i915/intel_lspcon.c > >@@ -158,6 +158,8 @@ static bool lspcon_probe(struct intel_lspcon *lspcon) > > static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) > > { > > struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon); > >+ struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); > >+ struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); > > unsigned long start = jiffies; > > if (!lspcon->desc_valid) > >@@ -173,7 +175,8 @@ static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) > > if (!__intel_dp_read_desc(intel_dp, &desc)) > > return; > >- if (!memcmp(&intel_dp->desc, &desc, sizeof(desc))) { > >+ if (intel_digital_port_connected(dev_priv, dig_port) && > when in PCON mode, live_status is always up for LSPCON port, so this check > will be always true, isn't it ? Not at least in case of the MegaChips LSPCON I've seen, there it takes a while for HPD to get asserted. And while it's not asserted AUX transactions will either: - return garbage in case of native AUX transactions - hang the chip/FW until next cold reboot in case of I2C-over-AUX transactions - simply not get a reply if the chip/FW initialization has reached a certain phase Based on the DP specification the sink/branch device is not required to respond in case the HPD is not asserted, so the 3rd scenario is compliant, but the first two are not. In PCON mode after initialization and HPD getting asserted, HPD will stay asserted except for the short pulses signaling an output connect/disconnect. --Imre > - Shashank > >+ !memcmp(&intel_dp->desc, &desc, sizeof(desc))) { > > DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n", > > jiffies_to_msecs(jiffies - start)); > > return; >
Regards Shashank On 1/28/2017 1:47 PM, Imre Deak wrote: > On Sat, Jan 28, 2017 at 10:32:03AM +0530, Sharma, Shashank wrote: >> Regards >> >> Shashank >> >> >> On 1/27/2017 3:09 PM, Imre Deak wrote: >>> During system resume time initialization the HPD level on LSPCON ports >>> can stay low for an extended amount of time, leading to failed AUX >>> transfers and LSPCON initialization. Fix this by waiting for HPD to get >>> asserted. >>> >>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99178 >>> Cc: Shashank Sharma <shashank.sharma@intel.com> >>> Cc: Jani Nikula <jani.nikula@linux.intel.com> >>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> >>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> >>> Cc: <stable@vger.kernel.org> # v4.9+ >>> Signed-off-by: Imre Deak <imre.deak@intel.com> >>> --- >>> drivers/gpu/drm/i915/intel_dp.c | 4 ++-- >>> drivers/gpu/drm/i915/intel_drv.h | 2 ++ >>> drivers/gpu/drm/i915/intel_lspcon.c | 5 ++++- >>> 3 files changed, 8 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c >>> index e0f9b9e..a7785ce 100644 >>> --- a/drivers/gpu/drm/i915/intel_dp.c >>> +++ b/drivers/gpu/drm/i915/intel_dp.c >>> @@ -4400,8 +4400,8 @@ static bool bxt_digital_port_connected(struct drm_i915_private *dev_priv, >>> * >>> * Return %true if @port is connected, %false otherwise. >>> */ >>> -static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, >>> - struct intel_digital_port *port) >>> +bool intel_digital_port_connected(struct drm_i915_private *dev_priv, >>> + struct intel_digital_port *port) >>> { >>> if (HAS_PCH_IBX(dev_priv)) >>> return ibx_digital_port_connected(dev_priv, port); >>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h >>> index b71fece..b9cde11 100644 >>> --- a/drivers/gpu/drm/i915/intel_drv.h >>> +++ b/drivers/gpu/drm/i915/intel_drv.h >>> @@ -1489,6 +1489,8 @@ bool __intel_dp_read_desc(struct intel_dp *intel_dp, >>> bool intel_dp_read_desc(struct intel_dp *intel_dp); >>> int intel_dp_link_required(int pixel_clock, int bpp); >>> int intel_dp_max_data_rate(int max_link_clock, int max_lanes); >>> +bool intel_digital_port_connected(struct drm_i915_private *dev_priv, >>> + struct intel_digital_port *port); >>> /* intel_dp_aux_backlight.c */ >>> int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector); >>> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c >>> index f6d4e69..c300647 100644 >>> --- a/drivers/gpu/drm/i915/intel_lspcon.c >>> +++ b/drivers/gpu/drm/i915/intel_lspcon.c >>> @@ -158,6 +158,8 @@ static bool lspcon_probe(struct intel_lspcon *lspcon) >>> static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) >>> { >>> struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon); >>> + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); >>> + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); >>> unsigned long start = jiffies; >>> if (!lspcon->desc_valid) >>> @@ -173,7 +175,8 @@ static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) >>> if (!__intel_dp_read_desc(intel_dp, &desc)) >>> return; >>> - if (!memcmp(&intel_dp->desc, &desc, sizeof(desc))) { >>> + if (intel_digital_port_connected(dev_priv, dig_port) && >> when in PCON mode, live_status is always up for LSPCON port, so this check >> will be always true, isn't it ? > Not at least in case of the MegaChips LSPCON I've seen, there it takes a > while for HPD to get asserted. And while it's not asserted AUX > transactions will either: > - return garbage in case of native AUX transactions > - hang the chip/FW until next cold reboot in case of I2C-over-AUX > transactions > - simply not get a reply if the chip/FW initialization has reached a > certain phase > > Based on the DP specification the sink/branch device is not required to > respond in case the HPD is not asserted, so the 3rd scenario is > compliant, but the first two are not. > > In PCON mode after initialization and HPD getting asserted, HPD will > stay asserted except for the short pulses signaling an output > connect/disconnect. The reason might be, that LSPCON resumes in LS type2 adapter state, where the live_status behavior is normal and reflects the real HPD line, but the moment we move to PCON mode, HPD gets asserted low. I know you would have tested this well, but I also want to test this code and logic first, before we go ahead with the patch. Shashank > --Imre > >> - Shashank >>> + !memcmp(&intel_dp->desc, &desc, sizeof(desc))) { >>> DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n", >>> jiffies_to_msecs(jiffies - start)); >>> return;
On Sun, Jan 29, 2017 at 10:33:07AM +0530, Sharma, Shashank wrote: > Regards > > Shashank > > > On 1/28/2017 1:47 PM, Imre Deak wrote: > >On Sat, Jan 28, 2017 at 10:32:03AM +0530, Sharma, Shashank wrote: > >>Regards > >> > >>Shashank > >> > >> > >>On 1/27/2017 3:09 PM, Imre Deak wrote: > >>>During system resume time initialization the HPD level on LSPCON ports > >>>can stay low for an extended amount of time, leading to failed AUX > >>>transfers and LSPCON initialization. Fix this by waiting for HPD to get > >>>asserted. > >>> > >>>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99178 > >>>Cc: Shashank Sharma <shashank.sharma@intel.com> > >>>Cc: Jani Nikula <jani.nikula@linux.intel.com> > >>>Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > >>>Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > >>>Cc: <stable@vger.kernel.org> # v4.9+ > >>>Signed-off-by: Imre Deak <imre.deak@intel.com> > >>>--- > >>> drivers/gpu/drm/i915/intel_dp.c | 4 ++-- > >>> drivers/gpu/drm/i915/intel_drv.h | 2 ++ > >>> drivers/gpu/drm/i915/intel_lspcon.c | 5 ++++- > >>> 3 files changed, 8 insertions(+), 3 deletions(-) > >>> > >>>diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > >>>index e0f9b9e..a7785ce 100644 > >>>--- a/drivers/gpu/drm/i915/intel_dp.c > >>>+++ b/drivers/gpu/drm/i915/intel_dp.c > >>>@@ -4400,8 +4400,8 @@ static bool bxt_digital_port_connected(struct drm_i915_private *dev_priv, > >>> * > >>> * Return %true if @port is connected, %false otherwise. > >>> */ > >>>-static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > >>>- struct intel_digital_port *port) > >>>+bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > >>>+ struct intel_digital_port *port) > >>> { > >>> if (HAS_PCH_IBX(dev_priv)) > >>> return ibx_digital_port_connected(dev_priv, port); > >>>diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > >>>index b71fece..b9cde11 100644 > >>>--- a/drivers/gpu/drm/i915/intel_drv.h > >>>+++ b/drivers/gpu/drm/i915/intel_drv.h > >>>@@ -1489,6 +1489,8 @@ bool __intel_dp_read_desc(struct intel_dp *intel_dp, > >>> bool intel_dp_read_desc(struct intel_dp *intel_dp); > >>> int intel_dp_link_required(int pixel_clock, int bpp); > >>> int intel_dp_max_data_rate(int max_link_clock, int max_lanes); > >>>+bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > >>>+ struct intel_digital_port *port); > >>> /* intel_dp_aux_backlight.c */ > >>> int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector); > >>>diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c > >>>index f6d4e69..c300647 100644 > >>>--- a/drivers/gpu/drm/i915/intel_lspcon.c > >>>+++ b/drivers/gpu/drm/i915/intel_lspcon.c > >>>@@ -158,6 +158,8 @@ static bool lspcon_probe(struct intel_lspcon *lspcon) > >>> static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) > >>> { > >>> struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon); > >>>+ struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); > >>>+ struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); > >>> unsigned long start = jiffies; > >>> if (!lspcon->desc_valid) > >>>@@ -173,7 +175,8 @@ static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) > >>> if (!__intel_dp_read_desc(intel_dp, &desc)) > >>> return; > >>>- if (!memcmp(&intel_dp->desc, &desc, sizeof(desc))) { > >>>+ if (intel_digital_port_connected(dev_priv, dig_port) && > >>when in PCON mode, live_status is always up for LSPCON port, so this check > >>will be always true, isn't it ? > >Not at least in case of the MegaChips LSPCON I've seen, there it takes a > >while for HPD to get asserted. And while it's not asserted AUX > >transactions will either: > >- return garbage in case of native AUX transactions > >- hang the chip/FW until next cold reboot in case of I2C-over-AUX > > transactions > >- simply not get a reply if the chip/FW initialization has reached a > > certain phase > > > >Based on the DP specification the sink/branch device is not required to > >respond in case the HPD is not asserted, so the 3rd scenario is > >compliant, but the first two are not. > > > >In PCON mode after initialization and HPD getting asserted, HPD will > >stay asserted except for the short pulses signaling an output > >connect/disconnect. > The reason might be, that LSPCON resumes in LS type2 adapter state, where > the live_status behavior is normal > and reflects the real HPD line, but the moment we move to PCON mode, HPD > gets asserted low. No, this chip/firmware resumes in PCON mode not in LS mode. Otherwise native AUX transfers wouldn't return any reply (per LSPCON specification) and HPD wouldn't get asserted on its own without a display connected. Notice that we only check the LS/PCON state and change it to PCON mode if necessary only after HPD gets asserted. --Imre > I know you would have tested this well, but I also want to test this code > and logic first, before we go ahead with the patch. > > Shashank > >--Imre > > > >>- Shashank > >>>+ !memcmp(&intel_dp->desc, &desc, sizeof(desc))) { > >>> DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n", > >>> jiffies_to_msecs(jiffies - start)); > >>> return; >
Reviewed-by: Shashank Sharma Regards Shashank On 1/29/2017 9:43 PM, Imre Deak wrote: > On Sun, Jan 29, 2017 at 10:33:07AM +0530, Sharma, Shashank wrote: >> Regards >> >> Shashank >> >> >> On 1/28/2017 1:47 PM, Imre Deak wrote: >>> On Sat, Jan 28, 2017 at 10:32:03AM +0530, Sharma, Shashank wrote: >>>> Regards >>>> >>>> Shashank >>>> >>>> >>>> On 1/27/2017 3:09 PM, Imre Deak wrote: >>>>> During system resume time initialization the HPD level on LSPCON ports >>>>> can stay low for an extended amount of time, leading to failed AUX >>>>> transfers and LSPCON initialization. Fix this by waiting for HPD to get >>>>> asserted. >>>>> >>>>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99178 >>>>> Cc: Shashank Sharma <shashank.sharma@intel.com> >>>>> Cc: Jani Nikula <jani.nikula@linux.intel.com> >>>>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> >>>>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> >>>>> Cc: <stable@vger.kernel.org> # v4.9+ >>>>> Signed-off-by: Imre Deak <imre.deak@intel.com> >>>>> --- >>>>> drivers/gpu/drm/i915/intel_dp.c | 4 ++-- >>>>> drivers/gpu/drm/i915/intel_drv.h | 2 ++ >>>>> drivers/gpu/drm/i915/intel_lspcon.c | 5 ++++- >>>>> 3 files changed, 8 insertions(+), 3 deletions(-) >>>>> >>>>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c >>>>> index e0f9b9e..a7785ce 100644 >>>>> --- a/drivers/gpu/drm/i915/intel_dp.c >>>>> +++ b/drivers/gpu/drm/i915/intel_dp.c >>>>> @@ -4400,8 +4400,8 @@ static bool bxt_digital_port_connected(struct drm_i915_private *dev_priv, >>>>> * >>>>> * Return %true if @port is connected, %false otherwise. >>>>> */ >>>>> -static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, >>>>> - struct intel_digital_port *port) >>>>> +bool intel_digital_port_connected(struct drm_i915_private *dev_priv, >>>>> + struct intel_digital_port *port) >>>>> { >>>>> if (HAS_PCH_IBX(dev_priv)) >>>>> return ibx_digital_port_connected(dev_priv, port); >>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h >>>>> index b71fece..b9cde11 100644 >>>>> --- a/drivers/gpu/drm/i915/intel_drv.h >>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h >>>>> @@ -1489,6 +1489,8 @@ bool __intel_dp_read_desc(struct intel_dp *intel_dp, >>>>> bool intel_dp_read_desc(struct intel_dp *intel_dp); >>>>> int intel_dp_link_required(int pixel_clock, int bpp); >>>>> int intel_dp_max_data_rate(int max_link_clock, int max_lanes); >>>>> +bool intel_digital_port_connected(struct drm_i915_private *dev_priv, >>>>> + struct intel_digital_port *port); >>>>> /* intel_dp_aux_backlight.c */ >>>>> int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector); >>>>> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c >>>>> index f6d4e69..c300647 100644 >>>>> --- a/drivers/gpu/drm/i915/intel_lspcon.c >>>>> +++ b/drivers/gpu/drm/i915/intel_lspcon.c >>>>> @@ -158,6 +158,8 @@ static bool lspcon_probe(struct intel_lspcon *lspcon) >>>>> static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) >>>>> { >>>>> struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon); >>>>> + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); >>>>> + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); >>>>> unsigned long start = jiffies; >>>>> if (!lspcon->desc_valid) >>>>> @@ -173,7 +175,8 @@ static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) >>>>> if (!__intel_dp_read_desc(intel_dp, &desc)) >>>>> return; >>>>> - if (!memcmp(&intel_dp->desc, &desc, sizeof(desc))) { >>>>> + if (intel_digital_port_connected(dev_priv, dig_port) && >>>> when in PCON mode, live_status is always up for LSPCON port, so this check >>>> will be always true, isn't it ? >>> Not at least in case of the MegaChips LSPCON I've seen, there it takes a >>> while for HPD to get asserted. And while it's not asserted AUX >>> transactions will either: >>> - return garbage in case of native AUX transactions >>> - hang the chip/FW until next cold reboot in case of I2C-over-AUX >>> transactions >>> - simply not get a reply if the chip/FW initialization has reached a >>> certain phase >>> >>> Based on the DP specification the sink/branch device is not required to >>> respond in case the HPD is not asserted, so the 3rd scenario is >>> compliant, but the first two are not. >>> >>> In PCON mode after initialization and HPD getting asserted, HPD will >>> stay asserted except for the short pulses signaling an output >>> connect/disconnect. >> The reason might be, that LSPCON resumes in LS type2 adapter state, where >> the live_status behavior is normal >> and reflects the real HPD line, but the moment we move to PCON mode, HPD >> gets asserted low. > No, this chip/firmware resumes in PCON mode not in LS mode. Otherwise > native AUX transfers wouldn't return any reply (per LSPCON > specification) and HPD wouldn't get asserted on its own without a > display connected. Notice that we only check the LS/PCON state and > change it to PCON mode if necessary only after HPD gets asserted. > > --Imre > >> I know you would have tested this well, but I also want to test this code >> and logic first, before we go ahead with the patch. >> >> Shashank >>> --Imre >>> >>>> - Shashank >>>>> + !memcmp(&intel_dp->desc, &desc, sizeof(desc))) { >>>>> DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n", >>>>> jiffies_to_msecs(jiffies - start)); >>>>> return;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index e0f9b9e..a7785ce 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4400,8 +4400,8 @@ static bool bxt_digital_port_connected(struct drm_i915_private *dev_priv, * * Return %true if @port is connected, %false otherwise. */ -static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, - struct intel_digital_port *port) +bool intel_digital_port_connected(struct drm_i915_private *dev_priv, + struct intel_digital_port *port) { if (HAS_PCH_IBX(dev_priv)) return ibx_digital_port_connected(dev_priv, port); diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index b71fece..b9cde11 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1489,6 +1489,8 @@ bool __intel_dp_read_desc(struct intel_dp *intel_dp, bool intel_dp_read_desc(struct intel_dp *intel_dp); int intel_dp_link_required(int pixel_clock, int bpp); int intel_dp_max_data_rate(int max_link_clock, int max_lanes); +bool intel_digital_port_connected(struct drm_i915_private *dev_priv, + struct intel_digital_port *port); /* intel_dp_aux_backlight.c */ int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector); diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c index f6d4e69..c300647 100644 --- a/drivers/gpu/drm/i915/intel_lspcon.c +++ b/drivers/gpu/drm/i915/intel_lspcon.c @@ -158,6 +158,8 @@ static bool lspcon_probe(struct intel_lspcon *lspcon) static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) { struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon); + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); unsigned long start = jiffies; if (!lspcon->desc_valid) @@ -173,7 +175,8 @@ static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon) if (!__intel_dp_read_desc(intel_dp, &desc)) return; - if (!memcmp(&intel_dp->desc, &desc, sizeof(desc))) { + if (intel_digital_port_connected(dev_priv, dig_port) && + !memcmp(&intel_dp->desc, &desc, sizeof(desc))) { DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n", jiffies_to_msecs(jiffies - start)); return;
During system resume time initialization the HPD level on LSPCON ports can stay low for an extended amount of time, leading to failed AUX transfers and LSPCON initialization. Fix this by waiting for HPD to get asserted. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99178 Cc: Shashank Sharma <shashank.sharma@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: <stable@vger.kernel.org> # v4.9+ Signed-off-by: Imre Deak <imre.deak@intel.com> --- drivers/gpu/drm/i915/intel_dp.c | 4 ++-- drivers/gpu/drm/i915/intel_drv.h | 2 ++ drivers/gpu/drm/i915/intel_lspcon.c | 5 ++++- 3 files changed, 8 insertions(+), 3 deletions(-)