| Message ID | 1464597519-16659-6-git-send-email-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, May 30, 2016 at 09:38:23AM +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. 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: Rafael Antognolli <rafael.antognolli@intel.com> > Cc: dri-devel@lists.freedesktop.org > --- > drivers/gpu/drm/drm_dp_helper.c | 18 +++++++++++++----- > include/drm/drm_dp_helper.h | 1 + > 2 files changed, 14 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index eeaf5a7c3aa7..e1900d386685 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -774,6 +774,17 @@ static const struct i2c_algorithm drm_dp_i2c_algo = { > .master_xfer = drm_dp_i2c_xfer, > }; > > +void drm_dp_aux_init(struct drm_dp_aux *aux) Needs kerneldoc. Pleas also cross-reference to drm_dp_aux_register. Didn't read all the i2c code to make sure stuff really works with just that, but makes sense. All three core patches also need an ack from Dave. -Daniel > +{ > + mutex_init(&aux->hw_mutex); > + rt_mutex_init(&aux->ddc.bus_lock); > + > + aux->ddc.algo = &drm_dp_i2c_algo; > + aux->ddc.algo_data = aux; > + aux->ddc.retries = 3; > +} > +EXPORT_SYMBOL(drm_dp_aux_init); > + > /** > * drm_dp_aux_register() - initialise and register aux channel > * @aux: DisplayPort AUX channel > @@ -784,11 +795,8 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) > { > int ret; > > - mutex_init(&aux->hw_mutex); > - > - aux->ddc.algo = &drm_dp_i2c_algo; > - aux->ddc.algo_data = aux; > - aux->ddc.retries = 3; > + 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 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
On Wed, Jun 01, 2016 at 11:49:03AM +0200, Daniel Vetter wrote: > On Mon, May 30, 2016 at 09:38:23AM +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. 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: Rafael Antognolli <rafael.antognolli@intel.com> > > Cc: dri-devel@lists.freedesktop.org > > --- > > drivers/gpu/drm/drm_dp_helper.c | 18 +++++++++++++----- > > include/drm/drm_dp_helper.h | 1 + > > 2 files changed, 14 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > > index eeaf5a7c3aa7..e1900d386685 100644 > > --- a/drivers/gpu/drm/drm_dp_helper.c > > +++ b/drivers/gpu/drm/drm_dp_helper.c > > @@ -774,6 +774,17 @@ static const struct i2c_algorithm drm_dp_i2c_algo = { > > .master_xfer = drm_dp_i2c_xfer, > > }; > > > > +void drm_dp_aux_init(struct drm_dp_aux *aux) > > Needs kerneldoc. Pleas also cross-reference to drm_dp_aux_register. Didn't > read all the i2c code to make sure stuff really works with just that, but > makes sense. Already added the kerneldoc (mostly copy'pasted from drm_dp_aux_register), but good job you didn't check the i2c code as it changed in v4.7. However, it motivated a better patch as i2c now allows for us to control the locking and so we can make the interaction between i2c and the drm_dp_aux->hw_mutex (used for the DPCD bypass) much clearer. -Chris
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index eeaf5a7c3aa7..e1900d386685 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -774,6 +774,17 @@ static const struct i2c_algorithm drm_dp_i2c_algo = { .master_xfer = drm_dp_i2c_xfer, }; +void drm_dp_aux_init(struct drm_dp_aux *aux) +{ + mutex_init(&aux->hw_mutex); + rt_mutex_init(&aux->ddc.bus_lock); + + aux->ddc.algo = &drm_dp_i2c_algo; + aux->ddc.algo_data = aux; + aux->ddc.retries = 3; +} +EXPORT_SYMBOL(drm_dp_aux_init); + /** * drm_dp_aux_register() - initialise and register aux channel * @aux: DisplayPort AUX channel @@ -784,11 +795,8 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) { int ret; - mutex_init(&aux->hw_mutex); - - aux->ddc.algo = &drm_dp_i2c_algo; - aux->ddc.algo_data = aux; - aux->ddc.retries = 3; + 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);
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. 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: Rafael Antognolli <rafael.antognolli@intel.com> Cc: dri-devel@lists.freedesktop.org --- drivers/gpu/drm/drm_dp_helper.c | 18 +++++++++++++----- include/drm/drm_dp_helper.h | 1 + 2 files changed, 14 insertions(+), 5 deletions(-)