| Message ID | 1481071431-4252-1-git-send-email-manasi.d.navare@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 07 Dec 2016, Manasi Navare <manasi.d.navare@intel.com> wrote: > The detect_done flag was introduced in the commit > 7d23e3c37bb3fc6952dc84007ee60cb533fd2d5c in order to avoid The preferred format to cite commits is: 7d23e3c37bb3 ("drm/i915: Cleaning up intel_dp_hpd_pulse") or commit 7d23e3c37bb3fc6952dc84007ee60cb533fd2d5c Author: Shubhangi Shrivastava <shubhangi.shrivastava@intel.com> Date: Wed Mar 30 18:05:23 2016 +0530 drm/i915: Cleaning up intel_dp_hpd_pulse > multiple detects on hotplug where intel_dp_long_pulse() > was called from HPD handler as well as in intel_dp_detect. > So this detect_done flag was required to make sure intel_dp_detect() > did not call long pulse handler again if it was already been called > from HPD handler. However commit 1015811609c0328b5ed670d07748591b837e74eb 1015811609c0 ("drm/i915: Move long hpd handling into the hotplug work") > differs the long hpd handling entirely until the hotplug work runs to > avoid the double long hpd handling the "detect_done" flag is trying > to prevent. > > So now we do not need to reset the detect_done flag to false in > intel_dp_detect. It will be reset in the intel_dp_hpd_pulse so > that intel_dp_detect does a full detect. However if the .detect > gets called during mode enumeration then we do not need to do a > full detect. This patch avoids the WARNS_ONS during connected boot Please include such a backtrace in the commit message; it makes matching bugs and fixes so much easier. IIUC the warnings were introduced by 1015811609c0 ("drm/i915: Move long hpd handling into the hotplug work"), and that's cc: stable, so this one should be too, along with Fixes: 1015811609c0 ("drm/i915: Move long hpd handling into the hotplug work") Cc: stable@vger.kernel.org Of course, someone(tm) will still need to make sure this is the right fix... BR, Jani. > case when it calls intel_dp_check_link_status() due to multiple > detects and also avoids DP compliance failures. It avoids doing > a full detect every single time on .detect(). > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > --- > drivers/gpu/drm/i915/intel_dp.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index db75bb9..9c9277e 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -4470,8 +4470,6 @@ static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > if (!intel_dp->detect_done) > status = intel_dp_long_pulse(intel_dp->attached_connector); > > - intel_dp->detect_done = false; > - > return status; > }
On Tue, Dec 06, 2016 at 04:43:51PM -0800, Manasi Navare wrote: > The detect_done flag was introduced in the commit > 7d23e3c37bb3fc6952dc84007ee60cb533fd2d5c in order to avoid > multiple detects on hotplug where intel_dp_long_pulse() > was called from HPD handler as well as in intel_dp_detect. > So this detect_done flag was required to make sure intel_dp_detect() > did not call long pulse handler again if it was already been called > from HPD handler. However commit 1015811609c0328b5ed670d07748591b837e74eb > differs the long hpd handling entirely until the hotplug work runs to > avoid the double long hpd handling the "detect_done" flag is trying > to prevent. That sentence doesn't parse here. Anyways, the flag indeed is now a nop and your patch is pretty much the same what I did here: https://patchwork.freedesktop.org/patch/101476/ > > So now we do not need to reset the detect_done flag to false in > intel_dp_detect. It will be reset in the intel_dp_hpd_pulse so > that intel_dp_detect does a full detect. However if the .detect > gets called during mode enumeration then we do not need to do a > full detect. This patch avoids the WARNS_ONS during connected boot > case when it calls intel_dp_check_link_status() due to multiple > detects How exactly does it do that? Also we shouldn't sweep that under the rug anyway. Instead someone should actually fix the problem that causes the WARN. > and also avoids DP compliance failures. It avoids doing > a full detect every single time on .detect(). > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > --- > drivers/gpu/drm/i915/intel_dp.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index db75bb9..9c9277e 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -4470,8 +4470,6 @@ static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > if (!intel_dp->detect_done) > status = intel_dp_long_pulse(intel_dp->attached_connector); > > - intel_dp->detect_done = false; > - > return status; > } > > -- > 1.9.1
On Wed, Dec 07, 2016 at 04:05:56PM +0200, Ville Syrjälä wrote: > On Tue, Dec 06, 2016 at 04:43:51PM -0800, Manasi Navare wrote: > > The detect_done flag was introduced in the commit > > 7d23e3c37bb3fc6952dc84007ee60cb533fd2d5c in order to avoid > > multiple detects on hotplug where intel_dp_long_pulse() > > was called from HPD handler as well as in intel_dp_detect. > > So this detect_done flag was required to make sure intel_dp_detect() > > did not call long pulse handler again if it was already been called > > from HPD handler. However commit 1015811609c0328b5ed670d07748591b837e74eb > > differs the long hpd handling entirely until the hotplug work runs to > > avoid the double long hpd handling the "detect_done" flag is trying > > to prevent. > > That sentence doesn't parse here. Anyways, the flag indeed is now a nop > and your patch is pretty much the same what I did here: > https://patchwork.freedesktop.org/patch/101476/ > I looked at this patch and yes it is the same thing except that it keeps the name of the flag unchanged plus previous patch is too old and wont apply cleanly unless you rebase it. I will add the reseting of this flag in the resume case. Thoughts? > > > > So now we do not need to reset the detect_done flag to false in > > intel_dp_detect. It will be reset in the intel_dp_hpd_pulse so > > that intel_dp_detect does a full detect. However if the .detect > > gets called during mode enumeration then we do not need to do a > > full detect. This patch avoids the WARNS_ONS during connected boot > > case when it calls intel_dp_check_link_status() due to multiple > > detects > > How exactly does it do that? Also we shouldn't sweep that under the rug > anyway. Instead someone should actually fix the problem that causes the > WARN. > Actually an additional call to intel_dp_long_pulse from intel_dp_detect() because we are not resetting the detect_done flag, makes the function call intel_dp_check_link_status() in the case when intel_dp->lane_count is 0 and throws the WARN about that. So by resetting the flag we avoid this unwanted call to intel_dp_long_pulse and that gets rid of the warning. Manasi > > and also avoids DP compliance failures. It avoids doing > > a full detect every single time on .detect(). > > > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > > --- > > drivers/gpu/drm/i915/intel_dp.c | 2 -- > > 1 file changed, 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > > index db75bb9..9c9277e 100644 > > --- a/drivers/gpu/drm/i915/intel_dp.c > > +++ b/drivers/gpu/drm/i915/intel_dp.c > > @@ -4470,8 +4470,6 @@ static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > > if (!intel_dp->detect_done) > > status = intel_dp_long_pulse(intel_dp->attached_connector); > > > > - intel_dp->detect_done = false; > > - > > return status; > > } > > > > -- > > 1.9.1 > > -- > Ville Syrjälä > Intel OTC
Ville, You mentioned that this detect_done should be set to false also in the resume case so in i915_display_resume where it calls intel_hpd_init that eventually schedules the hpd_poll_init_work and calls drm_helper_hpd_irq_event() which then calls .detect(). So in this case if I have to reset this detect_done in the hpd_poll_init_work, how do I make sure I do it only if the connector is DP? Manasi On Wed, Dec 07, 2016 at 04:05:56PM +0200, Ville Syrjälä wrote: > On Tue, Dec 06, 2016 at 04:43:51PM -0800, Manasi Navare wrote: > > The detect_done flag was introduced in the commit > > 7d23e3c37bb3fc6952dc84007ee60cb533fd2d5c in order to avoid > > multiple detects on hotplug where intel_dp_long_pulse() > > was called from HPD handler as well as in intel_dp_detect. > > So this detect_done flag was required to make sure intel_dp_detect() > > did not call long pulse handler again if it was already been called > > from HPD handler. However commit 1015811609c0328b5ed670d07748591b837e74eb > > differs the long hpd handling entirely until the hotplug work runs to > > avoid the double long hpd handling the "detect_done" flag is trying > > to prevent. > > That sentence doesn't parse here. Anyways, the flag indeed is now a nop > and your patch is pretty much the same what I did here: > https://patchwork.freedesktop.org/patch/101476/ > > > > > So now we do not need to reset the detect_done flag to false in > > intel_dp_detect. It will be reset in the intel_dp_hpd_pulse so > > that intel_dp_detect does a full detect. However if the .detect > > gets called during mode enumeration then we do not need to do a > > full detect. This patch avoids the WARNS_ONS during connected boot > > case when it calls intel_dp_check_link_status() due to multiple > > detects > > How exactly does it do that? Also we shouldn't sweep that under the rug > anyway. Instead someone should actually fix the problem that causes the > WARN. > > > and also avoids DP compliance failures. It avoids doing > > a full detect every single time on .detect(). > > > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > > --- > > drivers/gpu/drm/i915/intel_dp.c | 2 -- > > 1 file changed, 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > > index db75bb9..9c9277e 100644 > > --- a/drivers/gpu/drm/i915/intel_dp.c > > +++ b/drivers/gpu/drm/i915/intel_dp.c > > @@ -4470,8 +4470,6 @@ static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > > if (!intel_dp->detect_done) > > status = intel_dp_long_pulse(intel_dp->attached_connector); > > > > - intel_dp->detect_done = false; > > - > > return status; > > } > > > > -- > > 1.9.1 > > -- > Ville Syrjälä > Intel OTC
On Wed, Dec 07, 2016 at 07:51:21PM -0800, Manasi Navare wrote: > Ville, > You mentioned that this detect_done should be set to false also > in the resume case so in i915_display_resume where it calls > intel_hpd_init that eventually schedules the hpd_poll_init_work and > calls drm_helper_hpd_irq_event() which then calls .detect(). > So in this case if I have to reset this detect_done in the > hpd_poll_init_work, how do I make sure I do it only if the > connector is DP? We have the .reset hook for these sort of things. > > Manasi > > On Wed, Dec 07, 2016 at 04:05:56PM +0200, Ville Syrjälä wrote: > > On Tue, Dec 06, 2016 at 04:43:51PM -0800, Manasi Navare wrote: > > > The detect_done flag was introduced in the commit > > > 7d23e3c37bb3fc6952dc84007ee60cb533fd2d5c in order to avoid > > > multiple detects on hotplug where intel_dp_long_pulse() > > > was called from HPD handler as well as in intel_dp_detect. > > > So this detect_done flag was required to make sure intel_dp_detect() > > > did not call long pulse handler again if it was already been called > > > from HPD handler. However commit 1015811609c0328b5ed670d07748591b837e74eb > > > differs the long hpd handling entirely until the hotplug work runs to > > > avoid the double long hpd handling the "detect_done" flag is trying > > > to prevent. > > > > That sentence doesn't parse here. Anyways, the flag indeed is now a nop > > and your patch is pretty much the same what I did here: > > https://patchwork.freedesktop.org/patch/101476/ > > > > > > > > So now we do not need to reset the detect_done flag to false in > > > intel_dp_detect. It will be reset in the intel_dp_hpd_pulse so > > > that intel_dp_detect does a full detect. However if the .detect > > > gets called during mode enumeration then we do not need to do a > > > full detect. This patch avoids the WARNS_ONS during connected boot > > > case when it calls intel_dp_check_link_status() due to multiple > > > detects > > > > How exactly does it do that? Also we shouldn't sweep that under the rug > > anyway. Instead someone should actually fix the problem that causes the > > WARN. > > > > > and also avoids DP compliance failures. It avoids doing > > > a full detect every single time on .detect(). > > > > > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > > > --- > > > drivers/gpu/drm/i915/intel_dp.c | 2 -- > > > 1 file changed, 2 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > > > index db75bb9..9c9277e 100644 > > > --- a/drivers/gpu/drm/i915/intel_dp.c > > > +++ b/drivers/gpu/drm/i915/intel_dp.c > > > @@ -4470,8 +4470,6 @@ static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > > > if (!intel_dp->detect_done) > > > status = intel_dp_long_pulse(intel_dp->attached_connector); > > > > > > - intel_dp->detect_done = false; > > > - > > > return status; > > > } > > > > > > -- > > > 1.9.1 > > > > -- > > Ville Syrjälä > > Intel OTC
On Thu, Dec 08, 2016 at 05:58:44PM +0200, Ville Syrjälä wrote: > On Wed, Dec 07, 2016 at 07:51:21PM -0800, Manasi Navare wrote: > > Ville, > > You mentioned that this detect_done should be set to false also > > in the resume case so in i915_display_resume where it calls > > intel_hpd_init that eventually schedules the hpd_poll_init_work and > > calls drm_helper_hpd_irq_event() which then calls .detect(). > > So in this case if I have to reset this detect_done in the > > hpd_poll_init_work, how do I make sure I do it only if the > > connector is DP? > > We have the .reset hook for these sort of things. > How can I use .reset hook to set the intel_dp->detect_done flag to false only for DP connector before sending drm_hpd_irq_event()? Manasi > > > > Manasi > > > > On Wed, Dec 07, 2016 at 04:05:56PM +0200, Ville Syrjälä wrote: > > > On Tue, Dec 06, 2016 at 04:43:51PM -0800, Manasi Navare wrote: > > > > The detect_done flag was introduced in the commit > > > > 7d23e3c37bb3fc6952dc84007ee60cb533fd2d5c in order to avoid > > > > multiple detects on hotplug where intel_dp_long_pulse() > > > > was called from HPD handler as well as in intel_dp_detect. > > > > So this detect_done flag was required to make sure intel_dp_detect() > > > > did not call long pulse handler again if it was already been called > > > > from HPD handler. However commit 1015811609c0328b5ed670d07748591b837e74eb > > > > differs the long hpd handling entirely until the hotplug work runs to > > > > avoid the double long hpd handling the "detect_done" flag is trying > > > > to prevent. > > > > > > That sentence doesn't parse here. Anyways, the flag indeed is now a nop > > > and your patch is pretty much the same what I did here: > > > https://patchwork.freedesktop.org/patch/101476/ > > > > > > > > > > > So now we do not need to reset the detect_done flag to false in > > > > intel_dp_detect. It will be reset in the intel_dp_hpd_pulse so > > > > that intel_dp_detect does a full detect. However if the .detect > > > > gets called during mode enumeration then we do not need to do a > > > > full detect. This patch avoids the WARNS_ONS during connected boot > > > > case when it calls intel_dp_check_link_status() due to multiple > > > > detects > > > > > > How exactly does it do that? Also we shouldn't sweep that under the rug > > > anyway. Instead someone should actually fix the problem that causes the > > > WARN. > > > > > > > and also avoids DP compliance failures. It avoids doing > > > > a full detect every single time on .detect(). > > > > > > > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > > > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > > > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > > > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > > > > --- > > > > drivers/gpu/drm/i915/intel_dp.c | 2 -- > > > > 1 file changed, 2 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > > > > index db75bb9..9c9277e 100644 > > > > --- a/drivers/gpu/drm/i915/intel_dp.c > > > > +++ b/drivers/gpu/drm/i915/intel_dp.c > > > > @@ -4470,8 +4470,6 @@ static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, > > > > if (!intel_dp->detect_done) > > > > status = intel_dp_long_pulse(intel_dp->attached_connector); > > > > > > > > - intel_dp->detect_done = false; > > > > - > > > > return status; > > > > } > > > > > > > > -- > > > > 1.9.1 > > > > > > -- > > > Ville Syrjälä > > > Intel OTC > > -- > Ville Syrjälä > Intel OTC
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index db75bb9..9c9277e 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4470,8 +4470,6 @@ static bool intel_digital_port_connected(struct drm_i915_private *dev_priv, if (!intel_dp->detect_done) status = intel_dp_long_pulse(intel_dp->attached_connector); - intel_dp->detect_done = false; - return status; }
The detect_done flag was introduced in the commit 7d23e3c37bb3fc6952dc84007ee60cb533fd2d5c in order to avoid multiple detects on hotplug where intel_dp_long_pulse() was called from HPD handler as well as in intel_dp_detect. So this detect_done flag was required to make sure intel_dp_detect() did not call long pulse handler again if it was already been called from HPD handler. However commit 1015811609c0328b5ed670d07748591b837e74eb differs the long hpd handling entirely until the hotplug work runs to avoid the double long hpd handling the "detect_done" flag is trying to prevent. So now we do not need to reset the detect_done flag to false in intel_dp_detect. It will be reset in the intel_dp_hpd_pulse so that intel_dp_detect does a full detect. However if the .detect gets called during mode enumeration then we do not need to do a full detect. This patch avoids the WARNS_ONS during connected boot case when it calls intel_dp_check_link_status() due to multiple detects and also avoids DP compliance failures. It avoids doing a full detect every single time on .detect(). Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> --- drivers/gpu/drm/i915/intel_dp.c | 2 -- 1 file changed, 2 deletions(-)