| Message ID | 91ec198dd95258dbf3bee2f6be739e0da73b4fdd.1495105635.git.jani.nikula@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/18/2017 04:10 AM, Jani Nikula wrote: > Face the fact, there are Display Port sink and branch devices out there > in the wild that don't follow the Display Port specifications, or they > have bugs, or just otherwise require special treatment. Start a common > quirk database the drivers can query based on the DP device > identification. At least for now, we leave the workarounds for the > drivers to implement as they see fit. > > For starters, add a branch device that can't handle full 24-bit main > link Mdiv and Ndiv main link attributes properly. Naturally, the > workaround of reducing main link attributes for all devices ended up in > regressions for other devices. So here we are. > > v2: Rebase on DRM DP desc read helpers > > v3: Fix the OUI memcmp blunder (Clint) Tested-by: Clinton Taylor <clinton.a.taylor@intel.com> Reviewed-by: Clinton Taylor <clinton.a.taylor@intel.com> > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> > Cc: Clint Taylor <clinton.a.taylor@intel.com> > Cc: Adam Jackson <ajax@redhat.com> > Cc: Harry Wentland <harry.wentland@amd.com> > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/drm_dp_helper.c | 52 +++++++++++++++++++++++++++++++++++++++-- > include/drm/drm_dp_helper.h | 32 +++++++++++++++++++++++++ > 2 files changed, 82 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 52e0ca9a5bb1..213fb837e1c4 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -1209,6 +1209,51 @@ int drm_dp_stop_crc(struct drm_dp_aux *aux) > } > EXPORT_SYMBOL(drm_dp_stop_crc); > > +struct dpcd_quirk { > + u8 oui[3]; > + bool is_branch; > + u32 quirks; > +}; > + > +#define OUI(first, second, third) { (first), (second), (third) } > + > +static const struct dpcd_quirk dpcd_quirk_list[] = { > + /* Analogix 7737 needs reduced M and N at HBR2 link rates */ > + { OUI(0x00, 0x22, 0xb9), true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, > +}; > + > +#undef OUI > + > +/* > + * Get a bit mask of DPCD quirks for the sink/branch device identified by > + * ident. The quirk data is shared but it's up to the drivers to act on the > + * data. > + * > + * For now, only the OUI (first three bytes) is used, but this may be extended > + * to device identification string and hardware/firmware revisions later. > + */ > +static u32 > +drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) > +{ > + const struct dpcd_quirk *quirk; > + u32 quirks = 0; > + int i; > + > + for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { > + quirk = &dpcd_quirk_list[i]; > + > + if (quirk->is_branch != is_branch) > + continue; > + > + if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) > + continue; > + > + quirks |= quirk->quirks; > + } > + > + return quirks; > +} > + > /** > * drm_dp_read_desc - read sink/branch descriptor from DPCD > * @aux: DisplayPort AUX channel > @@ -1231,14 +1276,17 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, > if (ret < 0) > return ret; > > + desc->quirks = drm_dp_get_quirks(ident, is_branch); > + > dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); > > - DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d\n", > + DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", > is_branch ? "branch" : "sink", > (int)sizeof(ident->oui), ident->oui, > dev_id_len, ident->device_id, > ident->hw_rev >> 4, ident->hw_rev & 0xf, > - ident->sw_major_rev, ident->sw_minor_rev); > + ident->sw_major_rev, ident->sw_minor_rev, > + desc->quirks); > > return 0; > } > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h > index aee5b96b51d7..717cb8496725 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -1090,12 +1090,44 @@ struct drm_dp_dpcd_ident { > /** > * struct drm_dp_desc - DP branch/sink device descriptor > * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch). > + * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks. > */ > struct drm_dp_desc { > struct drm_dp_dpcd_ident ident; > + u32 quirks; > }; > > int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, > bool is_branch); > > +/** > + * enum drm_dp_quirk - Display Port sink/branch device specific quirks > + * > + * Display Port sink and branch devices in the wild have a variety of bugs, try > + * to collect them here. The quirks are shared, but it's up to the drivers to > + * implement workarounds for them. > + */ > +enum drm_dp_quirk { > + /** > + * @DP_DPCD_QUIRK_LIMITED_M_N: > + * > + * The device requires main link attributes Mdiv and Ndiv to be limited > + * to 16 bits. > + */ > + DP_DPCD_QUIRK_LIMITED_M_N, > +}; > + > +/** > + * drm_dp_has_quirk() - does the DP device have a specific quirk > + * @desc: Device decriptor filled by drm_dp_read_desc() > + * @quirk: Quirk to query for > + * > + * Return true if DP device identified by @desc has @quirk. > + */ > +static inline bool > +drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk) > +{ > + return desc->quirks & BIT(quirk); > +} > + > #endif /* _DRM_DP_HELPER_H_ */
On Thu, 2017-05-18 at 14:10 +0300, Jani Nikula wrote: > Face the fact, there are Display Port sink and branch devices out there > in the wild that don't follow the Display Port specifications, or they > have bugs, or just otherwise require special treatment. Start a common > quirk database the drivers can query based on the DP device > identification. At least for now, we leave the workarounds for the > drivers to implement as they see fit. > > For starters, add a branch device that can't handle full 24-bit main > link Mdiv and Ndiv main link attributes properly. Naturally, the > workaround of reducing main link attributes for all devices ended up in > regressions for other devices. So here we are. > > v2: Rebase on DRM DP desc read helpers > > v3: Fix the OUI memcmp blunder (Clint) > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> > Cc: Clint Taylor <clinton.a.taylor@intel.com> > Cc: Adam Jackson <ajax@redhat.com> > Cc: Harry Wentland <harry.wentland@amd.com> > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/drm_dp_helper.c | 52 +++++++++++++++++++++++++++++++++++++++-- > include/drm/drm_dp_helper.h | 32 +++++++++++++++++++++++++ > 2 files changed, 82 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 52e0ca9a5bb1..213fb837e1c4 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c <snip> > + * enum drm_dp_quirk - Display Port sink/branch device specific quirks > + * > + * Display Port sink and branch devices in the wild have a variety of bugs, try > + * to collect them here. The quirks are shared, but it's up to the drivers to > + * implement workarounds for them. > + */ > +enum drm_dp_quirk { > + /** > + * @DP_DPCD_QUIRK_LIMITED_M_N: > + * > + * The device requires main link attributes Mdiv and Ndiv to be limited s/Mdiv/Mvid s/Ndiv/Nvid > + * to 16 bits. > + */ > + DP_DPCD_QUIRK_LIMITED_M_N, > +};
On 18.05.2017 13:10, Jani Nikula wrote: > Face the fact, there are Display Port sink and branch devices out there > in the wild that don't follow the Display Port specifications, or they > have bugs, or just otherwise require special treatment. Start a common > quirk database the drivers can query based on the DP device > identification. At least for now, we leave the workarounds for the > drivers to implement as they see fit. > > For starters, add a branch device that can't handle full 24-bit main > link Mdiv and Ndiv main link attributes properly. Naturally, the > workaround of reducing main link attributes for all devices ended up in > regressions for other devices. So here we are. > > v2: Rebase on DRM DP desc read helpers > > v3: Fix the OUI memcmp blunder (Clint) > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> > Cc: Clint Taylor <clinton.a.taylor@intel.com> > Cc: Adam Jackson <ajax@redhat.com> > Cc: Harry Wentland <harry.wentland@amd.com> > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/drm_dp_helper.c | 52 +++++++++++++++++++++++++++++++++++++++-- > include/drm/drm_dp_helper.h | 32 +++++++++++++++++++++++++ > 2 files changed, 82 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 52e0ca9a5bb1..213fb837e1c4 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -1209,6 +1209,51 @@ int drm_dp_stop_crc(struct drm_dp_aux *aux) > } > EXPORT_SYMBOL(drm_dp_stop_crc); > > +struct dpcd_quirk { > + u8 oui[3]; > + bool is_branch; > + u32 quirks; > +}; > + > +#define OUI(first, second, third) { (first), (second), (third) } > + > +static const struct dpcd_quirk dpcd_quirk_list[] = { > + /* Analogix 7737 needs reduced M and N at HBR2 link rates */ > + { OUI(0x00, 0x22, 0xb9), true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, > +}; > + > +#undef OUI > + Wouldn't be more clear this way: #define OUI_ANALOGIX {0x00, 0x22, 0xb9} static const struct dpcd_quirk dpcd_quirk_list[] = { { OUI_ANALOGIX, true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, }; Anyway, it seems the quirk is for all analogix branch devs, not only ANX7737, is it correct? Regards Andrzej > +/* > + * Get a bit mask of DPCD quirks for the sink/branch device identified by > + * ident. The quirk data is shared but it's up to the drivers to act on the > + * data. > + * > + * For now, only the OUI (first three bytes) is used, but this may be extended > + * to device identification string and hardware/firmware revisions later. > + */ > +static u32 > +drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) > +{ > + const struct dpcd_quirk *quirk; > + u32 quirks = 0; > + int i; > + > + for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { > + quirk = &dpcd_quirk_list[i]; > + > + if (quirk->is_branch != is_branch) > + continue; > + > + if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) > + continue; > + > + quirks |= quirk->quirks; > + } > + > + return quirks; > +} > + > /** > * drm_dp_read_desc - read sink/branch descriptor from DPCD > * @aux: DisplayPort AUX channel > @@ -1231,14 +1276,17 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, > if (ret < 0) > return ret; > > + desc->quirks = drm_dp_get_quirks(ident, is_branch); > + > dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); > > - DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d\n", > + DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", > is_branch ? "branch" : "sink", > (int)sizeof(ident->oui), ident->oui, > dev_id_len, ident->device_id, > ident->hw_rev >> 4, ident->hw_rev & 0xf, > - ident->sw_major_rev, ident->sw_minor_rev); > + ident->sw_major_rev, ident->sw_minor_rev, > + desc->quirks); > > return 0; > } > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h > index aee5b96b51d7..717cb8496725 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -1090,12 +1090,44 @@ struct drm_dp_dpcd_ident { > /** > * struct drm_dp_desc - DP branch/sink device descriptor > * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch). > + * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks. > */ > struct drm_dp_desc { > struct drm_dp_dpcd_ident ident; > + u32 quirks; > }; > > int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, > bool is_branch); > > +/** > + * enum drm_dp_quirk - Display Port sink/branch device specific quirks > + * > + * Display Port sink and branch devices in the wild have a variety of bugs, try > + * to collect them here. The quirks are shared, but it's up to the drivers to > + * implement workarounds for them. > + */ > +enum drm_dp_quirk { > + /** > + * @DP_DPCD_QUIRK_LIMITED_M_N: > + * > + * The device requires main link attributes Mdiv and Ndiv to be limited > + * to 16 bits. > + */ > + DP_DPCD_QUIRK_LIMITED_M_N, > +}; > + > +/** > + * drm_dp_has_quirk() - does the DP device have a specific quirk > + * @desc: Device decriptor filled by drm_dp_read_desc() > + * @quirk: Quirk to query for > + * > + * Return true if DP device identified by @desc has @quirk. > + */ > +static inline bool > +drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk) > +{ > + return desc->quirks & BIT(quirk); > +} > + > #endif /* _DRM_DP_HELPER_H_ */
On Fri, 19 May 2017, Andrzej Hajda <a.hajda@samsung.com> wrote: > On 18.05.2017 13:10, Jani Nikula wrote: >> Face the fact, there are Display Port sink and branch devices out there >> in the wild that don't follow the Display Port specifications, or they >> have bugs, or just otherwise require special treatment. Start a common >> quirk database the drivers can query based on the DP device >> identification. At least for now, we leave the workarounds for the >> drivers to implement as they see fit. >> >> For starters, add a branch device that can't handle full 24-bit main >> link Mdiv and Ndiv main link attributes properly. Naturally, the >> workaround of reducing main link attributes for all devices ended up in >> regressions for other devices. So here we are. >> >> v2: Rebase on DRM DP desc read helpers >> >> v3: Fix the OUI memcmp blunder (Clint) >> >> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> >> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> >> Cc: Clint Taylor <clinton.a.taylor@intel.com> >> Cc: Adam Jackson <ajax@redhat.com> >> Cc: Harry Wentland <harry.wentland@amd.com> >> Signed-off-by: Jani Nikula <jani.nikula@intel.com> >> --- >> drivers/gpu/drm/drm_dp_helper.c | 52 +++++++++++++++++++++++++++++++++++++++-- >> include/drm/drm_dp_helper.h | 32 +++++++++++++++++++++++++ >> 2 files changed, 82 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c >> index 52e0ca9a5bb1..213fb837e1c4 100644 >> --- a/drivers/gpu/drm/drm_dp_helper.c >> +++ b/drivers/gpu/drm/drm_dp_helper.c >> @@ -1209,6 +1209,51 @@ int drm_dp_stop_crc(struct drm_dp_aux *aux) >> } >> EXPORT_SYMBOL(drm_dp_stop_crc); >> >> +struct dpcd_quirk { >> + u8 oui[3]; >> + bool is_branch; >> + u32 quirks; >> +}; >> + >> +#define OUI(first, second, third) { (first), (second), (third) } >> + >> +static const struct dpcd_quirk dpcd_quirk_list[] = { >> + /* Analogix 7737 needs reduced M and N at HBR2 link rates */ >> + { OUI(0x00, 0x22, 0xb9), true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, >> +}; >> + >> +#undef OUI >> + > > Wouldn't be more clear this way: > > #define OUI_ANALOGIX {0x00, 0x22, 0xb9} > > static const struct dpcd_quirk dpcd_quirk_list[] = { > { OUI_ANALOGIX, true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, > }; Assuming we add more quirks like this later on, I prefer keeping my approach. > Anyway, it seems the quirk is for all analogix branch devs, not only > ANX7737, is it correct? True. I'm not sure if we have enough information to accurately limit this to just the affected devices. The check can be narrowed later on as needed. BR, Jani. > > Regards > Andrzej > >> +/* >> + * Get a bit mask of DPCD quirks for the sink/branch device identified by >> + * ident. The quirk data is shared but it's up to the drivers to act on the >> + * data. >> + * >> + * For now, only the OUI (first three bytes) is used, but this may be extended >> + * to device identification string and hardware/firmware revisions later. >> + */ >> +static u32 >> +drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) >> +{ >> + const struct dpcd_quirk *quirk; >> + u32 quirks = 0; >> + int i; >> + >> + for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { >> + quirk = &dpcd_quirk_list[i]; >> + >> + if (quirk->is_branch != is_branch) >> + continue; >> + >> + if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) >> + continue; >> + >> + quirks |= quirk->quirks; >> + } >> + >> + return quirks; >> +} >> + >> /** >> * drm_dp_read_desc - read sink/branch descriptor from DPCD >> * @aux: DisplayPort AUX channel >> @@ -1231,14 +1276,17 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, >> if (ret < 0) >> return ret; >> >> + desc->quirks = drm_dp_get_quirks(ident, is_branch); >> + >> dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); >> >> - DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d\n", >> + DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", >> is_branch ? "branch" : "sink", >> (int)sizeof(ident->oui), ident->oui, >> dev_id_len, ident->device_id, >> ident->hw_rev >> 4, ident->hw_rev & 0xf, >> - ident->sw_major_rev, ident->sw_minor_rev); >> + ident->sw_major_rev, ident->sw_minor_rev, >> + desc->quirks); >> >> return 0; >> } >> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h >> index aee5b96b51d7..717cb8496725 100644 >> --- a/include/drm/drm_dp_helper.h >> +++ b/include/drm/drm_dp_helper.h >> @@ -1090,12 +1090,44 @@ struct drm_dp_dpcd_ident { >> /** >> * struct drm_dp_desc - DP branch/sink device descriptor >> * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch). >> + * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks. >> */ >> struct drm_dp_desc { >> struct drm_dp_dpcd_ident ident; >> + u32 quirks; >> }; >> >> int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, >> bool is_branch); >> >> +/** >> + * enum drm_dp_quirk - Display Port sink/branch device specific quirks >> + * >> + * Display Port sink and branch devices in the wild have a variety of bugs, try >> + * to collect them here. The quirks are shared, but it's up to the drivers to >> + * implement workarounds for them. >> + */ >> +enum drm_dp_quirk { >> + /** >> + * @DP_DPCD_QUIRK_LIMITED_M_N: >> + * >> + * The device requires main link attributes Mdiv and Ndiv to be limited >> + * to 16 bits. >> + */ >> + DP_DPCD_QUIRK_LIMITED_M_N, >> +}; >> + >> +/** >> + * drm_dp_has_quirk() - does the DP device have a specific quirk >> + * @desc: Device decriptor filled by drm_dp_read_desc() >> + * @quirk: Quirk to query for >> + * >> + * Return true if DP device identified by @desc has @quirk. >> + */ >> +static inline bool >> +drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk) >> +{ >> + return desc->quirks & BIT(quirk); >> +} >> + >> #endif /* _DRM_DP_HELPER_H_ */ > >
On Thu, 18 May 2017, Clint Taylor <clinton.a.taylor@intel.com> wrote: > On 05/18/2017 04:10 AM, Jani Nikula wrote: >> Face the fact, there are Display Port sink and branch devices out there >> in the wild that don't follow the Display Port specifications, or they >> have bugs, or just otherwise require special treatment. Start a common >> quirk database the drivers can query based on the DP device >> identification. At least for now, we leave the workarounds for the >> drivers to implement as they see fit. >> >> For starters, add a branch device that can't handle full 24-bit main >> link Mdiv and Ndiv main link attributes properly. Naturally, the >> workaround of reducing main link attributes for all devices ended up in >> regressions for other devices. So here we are. >> >> v2: Rebase on DRM DP desc read helpers >> >> v3: Fix the OUI memcmp blunder (Clint) > > Tested-by: Clinton Taylor <clinton.a.taylor@intel.com> > Reviewed-by: Clinton Taylor <clinton.a.taylor@intel.com> I pushed the series to drm-intel topic/dp-quirks branch based on v4.12-rc3, with the goal of merging this to v4.12. Thanks for the review and testing so far; would you mind giving that branch a go too, to ensure I didn't screw anything up while applying? BR, Jani. > >> >> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> >> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> >> Cc: Clint Taylor <clinton.a.taylor@intel.com> >> Cc: Adam Jackson <ajax@redhat.com> >> Cc: Harry Wentland <harry.wentland@amd.com> >> Signed-off-by: Jani Nikula <jani.nikula@intel.com> >> --- >> drivers/gpu/drm/drm_dp_helper.c | 52 +++++++++++++++++++++++++++++++++++++++-- >> include/drm/drm_dp_helper.h | 32 +++++++++++++++++++++++++ >> 2 files changed, 82 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c >> index 52e0ca9a5bb1..213fb837e1c4 100644 >> --- a/drivers/gpu/drm/drm_dp_helper.c >> +++ b/drivers/gpu/drm/drm_dp_helper.c >> @@ -1209,6 +1209,51 @@ int drm_dp_stop_crc(struct drm_dp_aux *aux) >> } >> EXPORT_SYMBOL(drm_dp_stop_crc); >> >> +struct dpcd_quirk { >> + u8 oui[3]; >> + bool is_branch; >> + u32 quirks; >> +}; >> + >> +#define OUI(first, second, third) { (first), (second), (third) } >> + >> +static const struct dpcd_quirk dpcd_quirk_list[] = { >> + /* Analogix 7737 needs reduced M and N at HBR2 link rates */ >> + { OUI(0x00, 0x22, 0xb9), true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, >> +}; >> + >> +#undef OUI >> + >> +/* >> + * Get a bit mask of DPCD quirks for the sink/branch device identified by >> + * ident. The quirk data is shared but it's up to the drivers to act on the >> + * data. >> + * >> + * For now, only the OUI (first three bytes) is used, but this may be extended >> + * to device identification string and hardware/firmware revisions later. >> + */ >> +static u32 >> +drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) >> +{ >> + const struct dpcd_quirk *quirk; >> + u32 quirks = 0; >> + int i; >> + >> + for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { >> + quirk = &dpcd_quirk_list[i]; >> + >> + if (quirk->is_branch != is_branch) >> + continue; >> + >> + if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) >> + continue; >> + >> + quirks |= quirk->quirks; >> + } >> + >> + return quirks; >> +} >> + >> /** >> * drm_dp_read_desc - read sink/branch descriptor from DPCD >> * @aux: DisplayPort AUX channel >> @@ -1231,14 +1276,17 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, >> if (ret < 0) >> return ret; >> >> + desc->quirks = drm_dp_get_quirks(ident, is_branch); >> + >> dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); >> >> - DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d\n", >> + DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", >> is_branch ? "branch" : "sink", >> (int)sizeof(ident->oui), ident->oui, >> dev_id_len, ident->device_id, >> ident->hw_rev >> 4, ident->hw_rev & 0xf, >> - ident->sw_major_rev, ident->sw_minor_rev); >> + ident->sw_major_rev, ident->sw_minor_rev, >> + desc->quirks); >> >> return 0; >> } >> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h >> index aee5b96b51d7..717cb8496725 100644 >> --- a/include/drm/drm_dp_helper.h >> +++ b/include/drm/drm_dp_helper.h >> @@ -1090,12 +1090,44 @@ struct drm_dp_dpcd_ident { >> /** >> * struct drm_dp_desc - DP branch/sink device descriptor >> * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch). >> + * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks. >> */ >> struct drm_dp_desc { >> struct drm_dp_dpcd_ident ident; >> + u32 quirks; >> }; >> >> int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, >> bool is_branch); >> >> +/** >> + * enum drm_dp_quirk - Display Port sink/branch device specific quirks >> + * >> + * Display Port sink and branch devices in the wild have a variety of bugs, try >> + * to collect them here. The quirks are shared, but it's up to the drivers to >> + * implement workarounds for them. >> + */ >> +enum drm_dp_quirk { >> + /** >> + * @DP_DPCD_QUIRK_LIMITED_M_N: >> + * >> + * The device requires main link attributes Mdiv and Ndiv to be limited >> + * to 16 bits. >> + */ >> + DP_DPCD_QUIRK_LIMITED_M_N, >> +}; >> + >> +/** >> + * drm_dp_has_quirk() - does the DP device have a specific quirk >> + * @desc: Device decriptor filled by drm_dp_read_desc() >> + * @quirk: Quirk to query for >> + * >> + * Return true if DP device identified by @desc has @quirk. >> + */ >> +static inline bool >> +drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk) >> +{ >> + return desc->quirks & BIT(quirk); >> +} >> + >> #endif /* _DRM_DP_HELPER_H_ */ >
On Thu, 18 May 2017, "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com> wrote: > On Thu, 2017-05-18 at 14:10 +0300, Jani Nikula wrote: >> Face the fact, there are Display Port sink and branch devices out there >> in the wild that don't follow the Display Port specifications, or they >> have bugs, or just otherwise require special treatment. Start a common >> quirk database the drivers can query based on the DP device >> identification. At least for now, we leave the workarounds for the >> drivers to implement as they see fit. >> >> For starters, add a branch device that can't handle full 24-bit main >> link Mdiv and Ndiv main link attributes properly. Naturally, the >> workaround of reducing main link attributes for all devices ended up in >> regressions for other devices. So here we are. >> >> v2: Rebase on DRM DP desc read helpers >> >> v3: Fix the OUI memcmp blunder (Clint) >> >> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> >> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> >> Cc: Clint Taylor <clinton.a.taylor@intel.com> >> Cc: Adam Jackson <ajax@redhat.com> >> Cc: Harry Wentland <harry.wentland@amd.com> >> Signed-off-by: Jani Nikula <jani.nikula@intel.com> >> --- >> drivers/gpu/drm/drm_dp_helper.c | 52 +++++++++++++++++++++++++++++++++++++++-- >> include/drm/drm_dp_helper.h | 32 +++++++++++++++++++++++++ >> 2 files changed, 82 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c >> index 52e0ca9a5bb1..213fb837e1c4 100644 >> --- a/drivers/gpu/drm/drm_dp_helper.c > > <snip> >> + * enum drm_dp_quirk - Display Port sink/branch device specific quirks >> + * >> + * Display Port sink and branch devices in the wild have a variety of bugs, try >> + * to collect them here. The quirks are shared, but it's up to the drivers to >> + * implement workarounds for them. >> + */ >> +enum drm_dp_quirk { >> + /** >> + * @DP_DPCD_QUIRK_LIMITED_M_N: >> + * >> + * The device requires main link attributes Mdiv and Ndiv to be limited > > s/Mdiv/Mvid > s/Ndiv/Nvid Thanks, I took the liberty of fixing this while applying. BR, Jani. > >> + * to 16 bits. >> + */ >> + DP_DPCD_QUIRK_LIMITED_M_N, >> +};
On 05/29/2017 04:06 AM, Jani Nikula wrote: > On Thu, 18 May 2017, Clint Taylor <clinton.a.taylor@intel.com> wrote: >> On 05/18/2017 04:10 AM, Jani Nikula wrote: >>> Face the fact, there are Display Port sink and branch devices out there >>> in the wild that don't follow the Display Port specifications, or they >>> have bugs, or just otherwise require special treatment. Start a common >>> quirk database the drivers can query based on the DP device >>> identification. At least for now, we leave the workarounds for the >>> drivers to implement as they see fit. >>> >>> For starters, add a branch device that can't handle full 24-bit main >>> link Mdiv and Ndiv main link attributes properly. Naturally, the >>> workaround of reducing main link attributes for all devices ended up in >>> regressions for other devices. So here we are. >>> >>> v2: Rebase on DRM DP desc read helpers >>> >>> v3: Fix the OUI memcmp blunder (Clint) >> Tested-by: Clinton Taylor <clinton.a.taylor@intel.com> >> Reviewed-by: Clinton Taylor <clinton.a.taylor@intel.com> > I pushed the series to drm-intel topic/dp-quirks branch based on > v4.12-rc3, with the goal of merging this to v4.12. Thanks for the review > and testing so far; would you mind giving that branch a go too, to > ensure I didn't screw anything up while applying? Topic branch appears to work as expected. Quirk is applied only to OUI 0x0022B9 and the n and m values are reduced. Topic branch is: Tested-by: Clinton Taylor <clinton.a.taylor@intel.com> -Clint > BR, > Jani. > > >>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> >>> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> >>> Cc: Clint Taylor <clinton.a.taylor@intel.com> >>> Cc: Adam Jackson <ajax@redhat.com> >>> Cc: Harry Wentland <harry.wentland@amd.com> >>> Signed-off-by: Jani Nikula <jani.nikula@intel.com> >>> --- >>> drivers/gpu/drm/drm_dp_helper.c | 52 +++++++++++++++++++++++++++++++++++++++-- >>> include/drm/drm_dp_helper.h | 32 +++++++++++++++++++++++++ >>> 2 files changed, 82 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c >>> index 52e0ca9a5bb1..213fb837e1c4 100644 >>> --- a/drivers/gpu/drm/drm_dp_helper.c >>> +++ b/drivers/gpu/drm/drm_dp_helper.c >>> @@ -1209,6 +1209,51 @@ int drm_dp_stop_crc(struct drm_dp_aux *aux) >>> } >>> EXPORT_SYMBOL(drm_dp_stop_crc); >>> >>> +struct dpcd_quirk { >>> + u8 oui[3]; >>> + bool is_branch; >>> + u32 quirks; >>> +}; >>> + >>> +#define OUI(first, second, third) { (first), (second), (third) } >>> + >>> +static const struct dpcd_quirk dpcd_quirk_list[] = { >>> + /* Analogix 7737 needs reduced M and N at HBR2 link rates */ >>> + { OUI(0x00, 0x22, 0xb9), true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, >>> +}; >>> + >>> +#undef OUI >>> + >>> +/* >>> + * Get a bit mask of DPCD quirks for the sink/branch device identified by >>> + * ident. The quirk data is shared but it's up to the drivers to act on the >>> + * data. >>> + * >>> + * For now, only the OUI (first three bytes) is used, but this may be extended >>> + * to device identification string and hardware/firmware revisions later. >>> + */ >>> +static u32 >>> +drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) >>> +{ >>> + const struct dpcd_quirk *quirk; >>> + u32 quirks = 0; >>> + int i; >>> + >>> + for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { >>> + quirk = &dpcd_quirk_list[i]; >>> + >>> + if (quirk->is_branch != is_branch) >>> + continue; >>> + >>> + if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) >>> + continue; >>> + >>> + quirks |= quirk->quirks; >>> + } >>> + >>> + return quirks; >>> +} >>> + >>> /** >>> * drm_dp_read_desc - read sink/branch descriptor from DPCD >>> * @aux: DisplayPort AUX channel >>> @@ -1231,14 +1276,17 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, >>> if (ret < 0) >>> return ret; >>> >>> + desc->quirks = drm_dp_get_quirks(ident, is_branch); >>> + >>> dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); >>> >>> - DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d\n", >>> + DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", >>> is_branch ? "branch" : "sink", >>> (int)sizeof(ident->oui), ident->oui, >>> dev_id_len, ident->device_id, >>> ident->hw_rev >> 4, ident->hw_rev & 0xf, >>> - ident->sw_major_rev, ident->sw_minor_rev); >>> + ident->sw_major_rev, ident->sw_minor_rev, >>> + desc->quirks); >>> >>> return 0; >>> } >>> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h >>> index aee5b96b51d7..717cb8496725 100644 >>> --- a/include/drm/drm_dp_helper.h >>> +++ b/include/drm/drm_dp_helper.h >>> @@ -1090,12 +1090,44 @@ struct drm_dp_dpcd_ident { >>> /** >>> * struct drm_dp_desc - DP branch/sink device descriptor >>> * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch). >>> + * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks. >>> */ >>> struct drm_dp_desc { >>> struct drm_dp_dpcd_ident ident; >>> + u32 quirks; >>> }; >>> >>> int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, >>> bool is_branch); >>> >>> +/** >>> + * enum drm_dp_quirk - Display Port sink/branch device specific quirks >>> + * >>> + * Display Port sink and branch devices in the wild have a variety of bugs, try >>> + * to collect them here. The quirks are shared, but it's up to the drivers to >>> + * implement workarounds for them. >>> + */ >>> +enum drm_dp_quirk { >>> + /** >>> + * @DP_DPCD_QUIRK_LIMITED_M_N: >>> + * >>> + * The device requires main link attributes Mdiv and Ndiv to be limited >>> + * to 16 bits. >>> + */ >>> + DP_DPCD_QUIRK_LIMITED_M_N, >>> +}; >>> + >>> +/** >>> + * drm_dp_has_quirk() - does the DP device have a specific quirk >>> + * @desc: Device decriptor filled by drm_dp_read_desc() >>> + * @quirk: Quirk to query for >>> + * >>> + * Return true if DP device identified by @desc has @quirk. >>> + */ >>> +static inline bool >>> +drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk) >>> +{ >>> + return desc->quirks & BIT(quirk); >>> +} >>> + >>> #endif /* _DRM_DP_HELPER_H_ */
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 52e0ca9a5bb1..213fb837e1c4 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1209,6 +1209,51 @@ int drm_dp_stop_crc(struct drm_dp_aux *aux) } EXPORT_SYMBOL(drm_dp_stop_crc); +struct dpcd_quirk { + u8 oui[3]; + bool is_branch; + u32 quirks; +}; + +#define OUI(first, second, third) { (first), (second), (third) } + +static const struct dpcd_quirk dpcd_quirk_list[] = { + /* Analogix 7737 needs reduced M and N at HBR2 link rates */ + { OUI(0x00, 0x22, 0xb9), true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, +}; + +#undef OUI + +/* + * Get a bit mask of DPCD quirks for the sink/branch device identified by + * ident. The quirk data is shared but it's up to the drivers to act on the + * data. + * + * For now, only the OUI (first three bytes) is used, but this may be extended + * to device identification string and hardware/firmware revisions later. + */ +static u32 +drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) +{ + const struct dpcd_quirk *quirk; + u32 quirks = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { + quirk = &dpcd_quirk_list[i]; + + if (quirk->is_branch != is_branch) + continue; + + if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) + continue; + + quirks |= quirk->quirks; + } + + return quirks; +} + /** * drm_dp_read_desc - read sink/branch descriptor from DPCD * @aux: DisplayPort AUX channel @@ -1231,14 +1276,17 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, if (ret < 0) return ret; + desc->quirks = drm_dp_get_quirks(ident, is_branch); + dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); - DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d\n", + DRM_DEBUG_KMS("DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", is_branch ? "branch" : "sink", (int)sizeof(ident->oui), ident->oui, dev_id_len, ident->device_id, ident->hw_rev >> 4, ident->hw_rev & 0xf, - ident->sw_major_rev, ident->sw_minor_rev); + ident->sw_major_rev, ident->sw_minor_rev, + desc->quirks); return 0; } diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index aee5b96b51d7..717cb8496725 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1090,12 +1090,44 @@ struct drm_dp_dpcd_ident { /** * struct drm_dp_desc - DP branch/sink device descriptor * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch). + * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks. */ struct drm_dp_desc { struct drm_dp_dpcd_ident ident; + u32 quirks; }; int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, bool is_branch); +/** + * enum drm_dp_quirk - Display Port sink/branch device specific quirks + * + * Display Port sink and branch devices in the wild have a variety of bugs, try + * to collect them here. The quirks are shared, but it's up to the drivers to + * implement workarounds for them. + */ +enum drm_dp_quirk { + /** + * @DP_DPCD_QUIRK_LIMITED_M_N: + * + * The device requires main link attributes Mdiv and Ndiv to be limited + * to 16 bits. + */ + DP_DPCD_QUIRK_LIMITED_M_N, +}; + +/** + * drm_dp_has_quirk() - does the DP device have a specific quirk + * @desc: Device decriptor filled by drm_dp_read_desc() + * @quirk: Quirk to query for + * + * Return true if DP device identified by @desc has @quirk. + */ +static inline bool +drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk) +{ + return desc->quirks & BIT(quirk); +} + #endif /* _DRM_DP_HELPER_H_ */
Face the fact, there are Display Port sink and branch devices out there in the wild that don't follow the Display Port specifications, or they have bugs, or just otherwise require special treatment. Start a common quirk database the drivers can query based on the DP device identification. At least for now, we leave the workarounds for the drivers to implement as they see fit. For starters, add a branch device that can't handle full 24-bit main link Mdiv and Ndiv main link attributes properly. Naturally, the workaround of reducing main link attributes for all devices ended up in regressions for other devices. So here we are. v2: Rebase on DRM DP desc read helpers v3: Fix the OUI memcmp blunder (Clint) Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Cc: Clint Taylor <clinton.a.taylor@intel.com> Cc: Adam Jackson <ajax@redhat.com> Cc: Harry Wentland <harry.wentland@amd.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> --- drivers/gpu/drm/drm_dp_helper.c | 52 +++++++++++++++++++++++++++++++++++++++-- include/drm/drm_dp_helper.h | 32 +++++++++++++++++++++++++ 2 files changed, 82 insertions(+), 2 deletions(-)