Ville Syrjälä
2021-Oct-15 19:33 UTC
[Nouveau] [PATCH 01/15] gpu/drm: make drm_add_edid_modes() consistent when updating connector->display_info
On Fri, Oct 15, 2021 at 09:24:06PM +0200, Claudio Suarez wrote:> On Fri, Oct 15, 2021 at 03:03:13PM +0300, Ville Syrj?l? wrote: > > On Fri, Oct 15, 2021 at 01:36:59PM +0200, Claudio Suarez wrote: > > > According to the documentation, drm_add_edid_modes > > > "... Also fills out the &drm_display_info structure and ELD in @connector > > > with any information which can be derived from the edid." > > > > > > drm_add_edid_modes accepts a struct edid *edid parameter which may have a > > > value or may be null. When it is not null, connector->display_info and > > > connector->eld are updated according to the edid. When edid=NULL, only > > > connector->eld is reset. Reset connector->display_info to be consistent > > > and accurate. > > > > > > Signed-off-by: Claudio Suarez <cssk at net-c.es> > > > --- > > > drivers/gpu/drm/drm_edid.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > > > index 6325877c5fd6..6cbe09b2357c 100644 > > > --- a/drivers/gpu/drm/drm_edid.c > > > +++ b/drivers/gpu/drm/drm_edid.c > > > @@ -5358,10 +5358,12 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid) > > > > > > if (edid == NULL) { > > > clear_eld(connector); > > > + drm_reset_display_info(connector); > > > return 0; > > > } > > > if (!drm_edid_is_valid(edid)) { > > > clear_eld(connector); > > > + drm_reset_display_info(connector); > > > > Looks easier if you pull both of those out from these branches and > > just call them unconditionally at the start. > > After looking at the full code, I am not sure. This is the code: > =================> int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid) > { > int num_modes = 0; > u32 quirks; > > if (edid == NULL) { > clear_eld(connector); > drm_reset_display_info(connector); <--- added by me > return 0; > } > if (!drm_edid_is_valid(edid)) { > clear_eld(connector); > drm_reset_display_info(connector); <--- added by me > drm_warn(connector->dev, "%s: EDID invalid.\n", > connector->name); > return 0; > } > > drm_edid_to_eld(connector, edid); > > quirks = drm_add_display_info(connector, edid); > etc... > ================> > If we move those out of these branches and edid != NULL, we are executing an > unnecessary clear_eld(connector) and an unnecessary drm_reset_display_info(connector) > because the fields will be set in the next drm_edid_to_eld(connector, edid) and > drm_add_display_info(connector, edid) > > Do we want this ?Seems fine by me. And maybe we could nuke the second drm_reset_display_info() from deeper inside drm_add_display_info()? Not sure if drm_add_display_info() still has to be able to operate standalone or not. Hmm. Another option is to just move all these NULL/invalid edid checks into drm_edid_to_eld() and drm_add_display_info(). -- Ville Syrj?l? Intel
Ville Syrjälä
2021-Oct-15 19:46 UTC
[Nouveau] [Intel-gfx] [PATCH 01/15] gpu/drm: make drm_add_edid_modes() consistent when updating connector->display_info
On Fri, Oct 15, 2021 at 10:33:29PM +0300, Ville Syrj?l? wrote:> On Fri, Oct 15, 2021 at 09:24:06PM +0200, Claudio Suarez wrote: > > On Fri, Oct 15, 2021 at 03:03:13PM +0300, Ville Syrj?l? wrote: > > > On Fri, Oct 15, 2021 at 01:36:59PM +0200, Claudio Suarez wrote: > > > > According to the documentation, drm_add_edid_modes > > > > "... Also fills out the &drm_display_info structure and ELD in @connector > > > > with any information which can be derived from the edid." > > > > > > > > drm_add_edid_modes accepts a struct edid *edid parameter which may have a > > > > value or may be null. When it is not null, connector->display_info and > > > > connector->eld are updated according to the edid. When edid=NULL, only > > > > connector->eld is reset. Reset connector->display_info to be consistent > > > > and accurate. > > > > > > > > Signed-off-by: Claudio Suarez <cssk at net-c.es> > > > > --- > > > > drivers/gpu/drm/drm_edid.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > > > > index 6325877c5fd6..6cbe09b2357c 100644 > > > > --- a/drivers/gpu/drm/drm_edid.c > > > > +++ b/drivers/gpu/drm/drm_edid.c > > > > @@ -5358,10 +5358,12 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid) > > > > > > > > if (edid == NULL) { > > > > clear_eld(connector); > > > > + drm_reset_display_info(connector); > > > > return 0; > > > > } > > > > if (!drm_edid_is_valid(edid)) { > > > > clear_eld(connector); > > > > + drm_reset_display_info(connector); > > > > > > Looks easier if you pull both of those out from these branches and > > > just call them unconditionally at the start. > > > > After looking at the full code, I am not sure. This is the code: > > =================> > int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid) > > { > > int num_modes = 0; > > u32 quirks; > > > > if (edid == NULL) { > > clear_eld(connector); > > drm_reset_display_info(connector); <--- added by me > > return 0; > > } > > if (!drm_edid_is_valid(edid)) { > > clear_eld(connector); > > drm_reset_display_info(connector); <--- added by me > > drm_warn(connector->dev, "%s: EDID invalid.\n", > > connector->name); > > return 0; > > } > > > > drm_edid_to_eld(connector, edid); > > > > quirks = drm_add_display_info(connector, edid); > > etc... > > ================> > > > If we move those out of these branches and edid != NULL, we are executing an > > unnecessary clear_eld(connector) and an unnecessary drm_reset_display_info(connector) > > because the fields will be set in the next drm_edid_to_eld(connector, edid) and > > drm_add_display_info(connector, edid) > > > > Do we want this ? > > Seems fine by me. And maybe we could nuke the second > drm_reset_display_info() from deeper inside drm_add_display_info()? > Not sure if drm_add_display_info() still has to be able to operate > standalone or not. > > Hmm. Another option is to just move all these NULL/invalid edid > checks into drm_edid_to_eld() and drm_add_display_info().But maybe that's not so easy. Would still need to bail out from drm_add_edid_modes() I guess. -- Ville Syrj?l? Intel
Claudio Suarez
2021-Oct-16 08:25 UTC
[Nouveau] [Freedreno] [PATCH 01/15] gpu/drm: make drm_add_edid_modes() consistent when updating connector->display_info
On Fri, Oct 15, 2021 at 10:33:29PM +0300, Ville Syrj?l? wrote:> On Fri, Oct 15, 2021 at 09:24:06PM +0200, Claudio Suarez wrote: > > On Fri, Oct 15, 2021 at 03:03:13PM +0300, Ville Syrj?l? wrote: > > > On Fri, Oct 15, 2021 at 01:36:59PM +0200, Claudio Suarez wrote: > > > > According to the documentation, drm_add_edid_modes > > > > "... Also fills out the &drm_display_info structure and ELD in @connector > > > > with any information which can be derived from the edid." > > > > > > > > drm_add_edid_modes accepts a struct edid *edid parameter which may have a > > > > value or may be null. When it is not null, connector->display_info and > > > > connector->eld are updated according to the edid. When edid=NULL, only > > > > connector->eld is reset. Reset connector->display_info to be consistent > > > > and accurate. > > > > > > > > Signed-off-by: Claudio Suarez <cssk at net-c.es> > > > > --- > > > > drivers/gpu/drm/drm_edid.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > > > > index 6325877c5fd6..6cbe09b2357c 100644 > > > > --- a/drivers/gpu/drm/drm_edid.c > > > > +++ b/drivers/gpu/drm/drm_edid.c > > > > @@ -5358,10 +5358,12 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid) > > > > > > > > if (edid == NULL) { > > > > clear_eld(connector); > > > > + drm_reset_display_info(connector); > > > > return 0; > > > > } > > > > if (!drm_edid_is_valid(edid)) { > > > > clear_eld(connector); > > > > + drm_reset_display_info(connector); > > > > > > Looks easier if you pull both of those out from these branches and > > > just call them unconditionally at the start. > > > > After looking at the full code, I am not sure. This is the code: > > =================> > int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid) > > { > > int num_modes = 0; > > u32 quirks; > > > > if (edid == NULL) { > > clear_eld(connector); > > drm_reset_display_info(connector); <--- added by me > > return 0; > > } > > if (!drm_edid_is_valid(edid)) { > > clear_eld(connector); > > drm_reset_display_info(connector); <--- added by me > > drm_warn(connector->dev, "%s: EDID invalid.\n", > > connector->name); > > return 0; > > } > > > > drm_edid_to_eld(connector, edid); > > > > quirks = drm_add_display_info(connector, edid); > > etc... > > ================> > > > If we move those out of these branches and edid != NULL, we are executing an > > unnecessary clear_eld(connector) and an unnecessary drm_reset_display_info(connector) > > because the fields will be set in the next drm_edid_to_eld(connector, edid) and > > drm_add_display_info(connector, edid) > > > > Do we want this ? > > Seems fine by me. And maybe we could nuke the second > drm_reset_display_info() from deeper inside drm_add_display_info()? > Not sure if drm_add_display_info() still has to be able to operate > standalone or not. > > Hmm. Another option is to just move all these NULL/invalid edid > checks into drm_edid_to_eld() and drm_add_display_info().I was thinking about this. We can use a boolean variable: ============== bool edid_is_invalid; edid_is_invalid = !drm_edid_is_valid(edid); if (edid == NULL || edid_is_invalid) { clear_eld(connector); drm_reset_display_info(connector); if (edid_is_invalid) drm_warn(connector->dev, "%s: EDID invalid.\n", connector->name); return 0; } drm_edid_to_eld(connector, edid); ... ==============Internally, drm_edid_is_valid() handles NULL pointers properly. It is a quite elegant solution with a small change in the original design, and it improves this part in the way you pointed out. Best regards, Claudio Suarez