* Re: [PATCH v3 06/33] drm: Minimally initialise drm_dp_aux [not found] ` <1464964636-3877-7-git-send-email-chris@chris-wilson.co.uk> @ 2016-06-03 14:59 ` Ville Syrjälä 2016-06-09 20:57 ` Chris Wilson 0 siblings, 1 reply; 4+ messages in thread From: Ville Syrjälä @ 2016-06-03 14:59 UTC (permalink / raw) To: Chris Wilson; +Cc: Wolfram Sang, intel-gfx, dri-devel, linux-i2c, Dave Airlie On Fri, Jun 03, 2016 at 03:36:49PM +0100, Chris Wilson wrote: > When trying to split up the initialisation phase and the registration > phase, one immediate problem encountered is trying to use our own i2c > devices before registration with userspace (to read EDID during device > discovery). drm_dp_aux in particular only offers an interface for setting > up the device *after* we have exposed the connector via sysfs. In order > to break the chicken-and-egg problem, export drm_dp_aux_init() to > minimally prepare the i2c device for internal use before > drm_connector_register(). > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Dave Airlie <airlied@redhat.com> > Cc: Rafael Antognolli <rafael.antognolli@intel.com> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > Cc: dri-devel@lists.freedesktop.org > --- > drivers/gpu/drm/drm_dp_helper.c | 26 +++++++++++++++++++++----- > include/drm/drm_dp_helper.h | 1 + > 2 files changed, 22 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 4b088afa21b2..9b4ec65e1de6 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -791,15 +791,16 @@ static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) > } > > /** > - * drm_dp_aux_register() - initialise and register aux channel > + * drm_dp_aux_init() - minimally initialise an aux channel > * @aux: DisplayPort AUX channel > * > - * Returns 0 on success or a negative error code on failure. > + * If you need to use the drm_dp_aux's i2c adapter prior to registering it > + * with the outside world, call drm_dp_aux_init() first. You must still > + * call drm_dp_aux_register() once the connector has been registered to > + * allow userspace access to the auxiliary DP channel. > */ > -int drm_dp_aux_register(struct drm_dp_aux *aux) > +void drm_dp_aux_init(struct drm_dp_aux *aux) > { > - int ret; > - > mutex_init(&aux->hw_mutex); > > aux->ddc.algo = &drm_dp_i2c_algo; > @@ -809,6 +810,21 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) > aux->ddc.lock_bus = lock_bus; > aux->ddc.trylock_bus = trylock_bus; > aux->ddc.unlock_bus = unlock_bus; > +} > +EXPORT_SYMBOL(drm_dp_aux_init); This doesn't feel very safe to me. To me it looks like the i2c core wasn't designed to have the adapter be used before i2c_add_adapter() is called. I guess it might work in this case since you provide your own lock vfuncs. I think someone should fix the i2c core to split i2c_add_adapter() & co. into init and register phases. Cc:ing i2c folks... > + > +/** > + * drm_dp_aux_register() - initialise and register aux channel > + * @aux: DisplayPort AUX channel > + * > + * Returns 0 on success or a negative error code on failure. > + */ > +int drm_dp_aux_register(struct drm_dp_aux *aux) > +{ > + int ret; > + > + if (!aux->ddc.algo) > + drm_dp_aux_init(aux); > > aux->ddc.class = I2C_CLASS_DDC; > aux->ddc.owner = THIS_MODULE; > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h > index 5a848e734422..4d85cf2874af 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -805,6 +805,7 @@ int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link); > int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link); > int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link); > > +void drm_dp_aux_init(struct drm_dp_aux *aux); > int drm_dp_aux_register(struct drm_dp_aux *aux); > void drm_dp_aux_unregister(struct drm_dp_aux *aux); > > -- > 2.8.1 -- Ville Syrjälä Intel OTC _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3 06/33] drm: Minimally initialise drm_dp_aux 2016-06-03 14:59 ` [PATCH v3 06/33] drm: Minimally initialise drm_dp_aux Ville Syrjälä @ 2016-06-09 20:57 ` Chris Wilson 2016-06-10 10:26 ` Ville Syrjälä 0 siblings, 1 reply; 4+ messages in thread From: Chris Wilson @ 2016-06-09 20:57 UTC (permalink / raw) To: Ville Syrjälä Cc: intel-gfx, Dave Airlie, Rafael Antognolli, dri-devel, linux-i2c, Wolfram Sang On Fri, Jun 03, 2016 at 05:59:11PM +0300, Ville Syrjälä wrote: > On Fri, Jun 03, 2016 at 03:36:49PM +0100, Chris Wilson wrote: > > When trying to split up the initialisation phase and the registration > > phase, one immediate problem encountered is trying to use our own i2c > > devices before registration with userspace (to read EDID during device > > discovery). drm_dp_aux in particular only offers an interface for setting > > up the device *after* we have exposed the connector via sysfs. In order > > to break the chicken-and-egg problem, export drm_dp_aux_init() to > > minimally prepare the i2c device for internal use before > > drm_connector_register(). > > > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > > Cc: Dave Airlie <airlied@redhat.com> > > Cc: Rafael Antognolli <rafael.antognolli@intel.com> > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Cc: dri-devel@lists.freedesktop.org > > --- > > drivers/gpu/drm/drm_dp_helper.c | 26 +++++++++++++++++++++----- > > include/drm/drm_dp_helper.h | 1 + > > 2 files changed, 22 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > > index 4b088afa21b2..9b4ec65e1de6 100644 > > --- a/drivers/gpu/drm/drm_dp_helper.c > > +++ b/drivers/gpu/drm/drm_dp_helper.c > > @@ -791,15 +791,16 @@ static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) > > } > > > > /** > > - * drm_dp_aux_register() - initialise and register aux channel > > + * drm_dp_aux_init() - minimally initialise an aux channel > > * @aux: DisplayPort AUX channel > > * > > - * Returns 0 on success or a negative error code on failure. > > + * If you need to use the drm_dp_aux's i2c adapter prior to registering it > > + * with the outside world, call drm_dp_aux_init() first. You must still > > + * call drm_dp_aux_register() once the connector has been registered to > > + * allow userspace access to the auxiliary DP channel. > > */ > > -int drm_dp_aux_register(struct drm_dp_aux *aux) > > +void drm_dp_aux_init(struct drm_dp_aux *aux) > > { > > - int ret; > > - > > mutex_init(&aux->hw_mutex); > > > > aux->ddc.algo = &drm_dp_i2c_algo; > > @@ -809,6 +810,21 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) > > aux->ddc.lock_bus = lock_bus; > > aux->ddc.trylock_bus = trylock_bus; > > aux->ddc.unlock_bus = unlock_bus; > > +} > > +EXPORT_SYMBOL(drm_dp_aux_init); > > This doesn't feel very safe to me. To me it looks like the i2c core > wasn't designed to have the adapter be used before i2c_add_adapter() > is called. I guess it might work in this case since you provide your > own lock vfuncs. > > I think someone should fix the i2c core to split i2c_add_adapter() > & co. into init and register phases. Cc:ing i2c folks... As you've seen, I sent the patches to split i2c_add_adapter() to allow for us to call i2c_init_adapter() here instead. It still requires the same basic review that this init (the same as above) is sufficient for using i2c_transfer(). I would like to get the regression fix completed without much futher ado - in particular, not depending upon landing an external patch. -Chris -- Chris Wilson, Intel Open Source Technology Centre ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3 06/33] drm: Minimally initialise drm_dp_aux 2016-06-09 20:57 ` Chris Wilson @ 2016-06-10 10:26 ` Ville Syrjälä 2016-06-10 10:50 ` Chris Wilson 0 siblings, 1 reply; 4+ messages in thread From: Ville Syrjälä @ 2016-06-10 10:26 UTC (permalink / raw) To: Chris Wilson, intel-gfx, Dave Airlie, Rafael Antognolli, dri-devel, linux-i2c, Wolfram Sang On Thu, Jun 09, 2016 at 09:57:24PM +0100, Chris Wilson wrote: > On Fri, Jun 03, 2016 at 05:59:11PM +0300, Ville Syrjälä wrote: > > On Fri, Jun 03, 2016 at 03:36:49PM +0100, Chris Wilson wrote: > > > When trying to split up the initialisation phase and the registration > > > phase, one immediate problem encountered is trying to use our own i2c > > > devices before registration with userspace (to read EDID during device > > > discovery). drm_dp_aux in particular only offers an interface for setting > > > up the device *after* we have exposed the connector via sysfs. In order > > > to break the chicken-and-egg problem, export drm_dp_aux_init() to > > > minimally prepare the i2c device for internal use before > > > drm_connector_register(). > > > > > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > > > Cc: Dave Airlie <airlied@redhat.com> > > > Cc: Rafael Antognolli <rafael.antognolli@intel.com> > > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > > > Cc: dri-devel@lists.freedesktop.org > > > --- > > > drivers/gpu/drm/drm_dp_helper.c | 26 +++++++++++++++++++++----- > > > include/drm/drm_dp_helper.h | 1 + > > > 2 files changed, 22 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > > > index 4b088afa21b2..9b4ec65e1de6 100644 > > > --- a/drivers/gpu/drm/drm_dp_helper.c > > > +++ b/drivers/gpu/drm/drm_dp_helper.c > > > @@ -791,15 +791,16 @@ static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) > > > } > > > > > > /** > > > - * drm_dp_aux_register() - initialise and register aux channel > > > + * drm_dp_aux_init() - minimally initialise an aux channel > > > * @aux: DisplayPort AUX channel > > > * > > > - * Returns 0 on success or a negative error code on failure. > > > + * If you need to use the drm_dp_aux's i2c adapter prior to registering it > > > + * with the outside world, call drm_dp_aux_init() first. You must still > > > + * call drm_dp_aux_register() once the connector has been registered to > > > + * allow userspace access to the auxiliary DP channel. > > > */ > > > -int drm_dp_aux_register(struct drm_dp_aux *aux) > > > +void drm_dp_aux_init(struct drm_dp_aux *aux) > > > { > > > - int ret; > > > - > > > mutex_init(&aux->hw_mutex); > > > > > > aux->ddc.algo = &drm_dp_i2c_algo; > > > @@ -809,6 +810,21 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) > > > aux->ddc.lock_bus = lock_bus; > > > aux->ddc.trylock_bus = trylock_bus; > > > aux->ddc.unlock_bus = unlock_bus; > > > +} > > > +EXPORT_SYMBOL(drm_dp_aux_init); > > > > This doesn't feel very safe to me. To me it looks like the i2c core > > wasn't designed to have the adapter be used before i2c_add_adapter() > > is called. I guess it might work in this case since you provide your > > own lock vfuncs. > > > > I think someone should fix the i2c core to split i2c_add_adapter() > > & co. into init and register phases. Cc:ing i2c folks... > > As you've seen, I sent the patches to split i2c_add_adapter() to allow for > us to call i2c_init_adapter() here instead. It still requires the same > basic review that this init (the same as above) is sufficient for using > i2c_transfer(). > > I would like to get the regression fix completed without much futher > ado - in particular, not depending upon landing an external patch. What regression is this? -- Ville Syrjälä Intel OTC ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3 06/33] drm: Minimally initialise drm_dp_aux 2016-06-10 10:26 ` Ville Syrjälä @ 2016-06-10 10:50 ` Chris Wilson 0 siblings, 0 replies; 4+ messages in thread From: Chris Wilson @ 2016-06-10 10:50 UTC (permalink / raw) To: Ville Syrjälä Cc: Wolfram Sang, intel-gfx, dri-devel, linux-i2c, Dave Airlie On Fri, Jun 10, 2016 at 01:26:24PM +0300, Ville Syrjälä wrote: > On Thu, Jun 09, 2016 at 09:57:24PM +0100, Chris Wilson wrote: > > On Fri, Jun 03, 2016 at 05:59:11PM +0300, Ville Syrjälä wrote: > > > On Fri, Jun 03, 2016 at 03:36:49PM +0100, Chris Wilson wrote: > > > > When trying to split up the initialisation phase and the registration > > > > phase, one immediate problem encountered is trying to use our own i2c > > > > devices before registration with userspace (to read EDID during device > > > > discovery). drm_dp_aux in particular only offers an interface for setting > > > > up the device *after* we have exposed the connector via sysfs. In order > > > > to break the chicken-and-egg problem, export drm_dp_aux_init() to > > > > minimally prepare the i2c device for internal use before > > > > drm_connector_register(). > > > > > > > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > > > > Cc: Dave Airlie <airlied@redhat.com> > > > > Cc: Rafael Antognolli <rafael.antognolli@intel.com> > > > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > > > > Cc: dri-devel@lists.freedesktop.org > > > > --- > > > > drivers/gpu/drm/drm_dp_helper.c | 26 +++++++++++++++++++++----- > > > > include/drm/drm_dp_helper.h | 1 + > > > > 2 files changed, 22 insertions(+), 5 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > > > > index 4b088afa21b2..9b4ec65e1de6 100644 > > > > --- a/drivers/gpu/drm/drm_dp_helper.c > > > > +++ b/drivers/gpu/drm/drm_dp_helper.c > > > > @@ -791,15 +791,16 @@ static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) > > > > } > > > > > > > > /** > > > > - * drm_dp_aux_register() - initialise and register aux channel > > > > + * drm_dp_aux_init() - minimally initialise an aux channel > > > > * @aux: DisplayPort AUX channel > > > > * > > > > - * Returns 0 on success or a negative error code on failure. > > > > + * If you need to use the drm_dp_aux's i2c adapter prior to registering it > > > > + * with the outside world, call drm_dp_aux_init() first. You must still > > > > + * call drm_dp_aux_register() once the connector has been registered to > > > > + * allow userspace access to the auxiliary DP channel. > > > > */ > > > > -int drm_dp_aux_register(struct drm_dp_aux *aux) > > > > +void drm_dp_aux_init(struct drm_dp_aux *aux) > > > > { > > > > - int ret; > > > > - > > > > mutex_init(&aux->hw_mutex); > > > > > > > > aux->ddc.algo = &drm_dp_i2c_algo; > > > > @@ -809,6 +810,21 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) > > > > aux->ddc.lock_bus = lock_bus; > > > > aux->ddc.trylock_bus = trylock_bus; > > > > aux->ddc.unlock_bus = unlock_bus; > > > > +} > > > > +EXPORT_SYMBOL(drm_dp_aux_init); > > > > > > This doesn't feel very safe to me. To me it looks like the i2c core > > > wasn't designed to have the adapter be used before i2c_add_adapter() > > > is called. I guess it might work in this case since you provide your > > > own lock vfuncs. > > > > > > I think someone should fix the i2c core to split i2c_add_adapter() > > > & co. into init and register phases. Cc:ing i2c folks... > > > > As you've seen, I sent the patches to split i2c_add_adapter() to allow for > > us to call i2c_init_adapter() here instead. It still requires the same > > basic review that this init (the same as above) is sufficient for using > > i2c_transfer(). > > > > I would like to get the regression fix completed without much futher > > ado - in particular, not depending upon landing an external patch. > > What regression is this? It all started from the unclaimed mmio access across suspend, which stems from never having touched a context before suspend. That in turn meant touching the delayed rps initialisation which ended up with Daniel saying that the entire init chain needs to be unravelled. Snowball. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel ^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-06-03 14:59 ` [PATCH v3 06/33] drm: Minimally initialise drm_dp_aux Ville Syrjälä
2016-06-09 20:57 ` Chris Wilson
2016-06-10 10:26 ` Ville Syrjälä
2016-06-10 10:50 ` Chris Wilson
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