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On Tue, Aug 11, 2020 at 04:04:56PM -0400, Lyude Paul wrote: > Since DP 1.3, it's been possible for DP receivers to specify an > additional set of DPCD capabilities, which can take precedence over the > capabilities reported at DP_DPCD_REV. > > Basically any device supporting DP is going to need to read these in an > identical manner, in particular nouveau, so let's go ahead and just move > this code out of i915 into a shared D...

Since DP 1.3, it's been possible for DP receivers to specify an additional set of DPCD capabilities, which can take precedence over the capabilities reported at DP_DPCD_REV. Basically any device supporting DP is going to need to read these in an identical manner, in particular nouveau, so let's go ahead and just move this code out of i915 into a shared DRM DP helper that we can...

Currently we use the drm_dp_dpcd_read_caps() helper in the DRM side of nouveau in order to read the DPCD of a DP connector, which makes sure we do the right thing and also check for extended DPCD caps. However, it turns out we're not currently doing this on the nvkm side since we don't have access to the drm_dp_aux structu...

...stream_read_info(). > > Note that when we do this, we also do make some functional changes while > we're at it: > * We always clear the downstream port info before trying to read it, > just to make things easier for the caller > * We skip reading downstream port info if the DPCD indicates that we > don't support downstream port info > * We only read as many bytes as needed for the reported number of > downstream ports, no sense in reading the whole thing every time > > Signed-off-by: Lyude Paul <lyude at redhat.com> > --- > drivers/gpu/...

...sier time with merging if they pull the pending patches for nouveau from Ben's tree before merging drm-misc-next. Lyude Paul (20): drm/nouveau/kms: Fix some indenting in nouveau_dp_detect() drm/nouveau/kms/nv50-: Remove open-coded drm_dp_read_desc() drm/nouveau/kms/nv50-: Just use drm_dp_dpcd_read() in nouveau_dp.c drm/nouveau/kms/nv50-: Use macros for DP registers in nouveau_dp.c drm/nouveau/kms: Don't clear DP_MST_CTRL DPCD in nv50_mstm_new() drm/nouveau/kms: Search for encoders' connectors properly drm/nouveau/kms/nv50-: Use drm_dp_dpcd_(readb|writeb)() in nv50_so...

...o a shared helper: drm_dp_read_downstream_info(). Note that when we do this, we also do make some functional changes while we're at it: * We always clear the downstream port info before trying to read it, just to make things easier for the caller * We skip reading downstream port info if the DPCD indicates that we don't support downstream port info * We only read as many bytes as needed for the reported number of downstream ports, no sense in reading the whole thing every time v2: * Fixup logic for calculating the downstream port length to account for the fact that downstream por...

...as clean this code up and implement missing DP features like the ones mentioned here before moving on to those tasks. Lyude Paul (20): drm/nouveau/kms: Fix some indenting in nouveau_dp_detect() drm/nouveau/kms/nv50-: Remove open-coded drm_dp_read_desc() drm/nouveau/kms/nv50-: Just use drm_dp_dpcd_read() in nouveau_dp.c drm/nouveau/kms/nv50-: Use macros for DP registers in nouveau_dp.c drm/nouveau/kms: Don't clear DP_MST_CTRL DPCD in nv50_mstm_new() drm/nouveau/kms: Search for encoders' connectors properly drm/nouveau/kms/nv50-: Use drm_dp_dpcd_(readb|writeb)() in nv50_so...

...o a shared helper: drm_dp_downstream_read_info(). Note that when we do this, we also do make some functional changes while we're at it: * We always clear the downstream port info before trying to read it, just to make things easier for the caller * We skip reading downstream port info if the DPCD indicates that we don't support downstream port info * We only read as many bytes as needed for the reported number of downstream ports, no sense in reading the whole thing every time v2: * Fixup logic for calculating the downstream port length to account for the fact that downstream por...

...as clean this code up and implement missing DP features like the ones mentioned here before moving on to those tasks. Lyude Paul (20): drm/nouveau/kms: Fix some indenting in nouveau_dp_detect() drm/nouveau/kms/nv50-: Remove open-coded drm_dp_read_desc() drm/nouveau/kms/nv50-: Just use drm_dp_dpcd_read() in nouveau_dp.c drm/nouveau/kms/nv50-: Use macros for DP registers in nouveau_dp.c drm/nouveau/kms: Don't clear DP_MST_CTRL DPCD in nv50_mstm_new() drm/nouveau/kms: Search for encoders' connectors properly drm/nouveau/kms/nv50-: Use drm_dp_dpcd_(readb|writeb)() in nv50_so...

...sier time with merging if they pull the pending patches for nouveau from Ben's tree before merging drm-misc-next. Lyude Paul (20): drm/nouveau/kms: Fix some indenting in nouveau_dp_detect() drm/nouveau/kms/nv50-: Remove open-coded drm_dp_read_desc() drm/nouveau/kms/nv50-: Just use drm_dp_dpcd_read() in nouveau_dp.c drm/nouveau/kms/nv50-: Use macros for DP registers in nouveau_dp.c drm/nouveau/kms: Don't clear DP_MST_CTRL DPCD in nv50_mstm_new() drm/nouveau/kms: Search for encoders' connectors properly drm/nouveau/kms/nv50-: Use drm_dp_dpcd_(readb|writeb)() in nv50_so...

...ds of 'u8[15]' {aka 'unsigned char[15]'} [-Warray-bounds=] 57 | #define __underlying_memcpy __builtin_memcpy | ^ ... ../drivers/gpu/drm/nouveau/nvif/outp.c:140:9: note: in expansion of macro 'memcpy' 140 | memcpy(args.dp.dpcd, dpcd, sizeof(args.dp.dpcd)); | ^~~~~~ ../drivers/gpu/drm/nouveau/nvif/outp.c:130:49: note: object 'dpcd' of size [0, 15] 130 | nvif_outp_acquire_dp(struct nvif_outp *outp, u8 dpcd[DP_RECEIVER_CAP_SIZE], | ~~~^~~~~~~~~~~~~~~...

...when we do this, we also do make some functional changes while > > > we're at it: > > > * We always clear the downstream port info before trying to read it, > > > just to make things easier for the caller > > > * We skip reading downstream port info if the DPCD indicates that we > > > don't support downstream port info > > > * We only read as many bytes as needed for the reported number of > > > downstream ports, no sense in reading the whole thing every time > > > > > > Signed-off-by: Lyude Paul <l...

...o a shared helper: drm_dp_downstream_read_info(). Note that when we do this, we also do make some functional changes while we're at it: * We always clear the downstream port info before trying to read it, just to make things easier for the caller * We skip reading downstream port info if the DPCD indicates that we don't support downstream port info * We only read as many bytes as needed for the reported number of downstream ports, no sense in reading the whole thing every time Signed-off-by: Lyude Paul <lyude at redhat.com> --- drivers/gpu/drm/drm_dp_helper.c | 32 ++...

This fixes some annoying issues on the P50-P52 with displays not being detected if they aren't plugged in at boot, and sometimes even when they are plugged in at boot. See: https://bugzilla.redhat.com/show_bug.cgi?id=1477182 Lyude Paul (2): drm/nouveau: Only write DP_MSTM_CTRL when needed drm/nouveau: Reset MST branching unit before enabling drivers/gpu/drm/nouveau/dispnv50/disp.c | 65

...> > Note that when we do this, we also do make some functional changes while > > we're at it: > > * We always clear the downstream port info before trying to read it, > > just to make things easier for the caller > > * We skip reading downstream port info if the DPCD indicates that we > > don't support downstream port info > > * We only read as many bytes as needed for the reported number of > > downstream ports, no sense in reading the whole thing every time > > > > Signed-off-by: Lyude Paul <lyude at redhat.com> &g...

...also do make some functional changes while > > > > we're at it: > > > > * We always clear the downstream port info before trying to read it, > > > > just to make things easier for the caller > > > > * We skip reading downstream port info if the DPCD indicates that we > > > > don't support downstream port info > > > > * We only read as many bytes as needed for the reported number of > > > > downstream ports, no sense in reading the whole thing every time > > > > > > > > Signed...

...ds of 'u8[15]' {aka 'unsigned char[15]'} [-Warray-bounds=] 57 | #define __underlying_memcpy __builtin_memcpy | ^ ... ../drivers/gpu/drm/nouveau/nvif/outp.c:140:9: note: in expansion of macro 'memcpy' 140 | memcpy(args.dp.dpcd, dpcd, sizeof(args.dp.dpcd)); | ^~~~~~ ../drivers/gpu/drm/nouveau/nvif/outp.c:130:49: note: object 'dpcd' of size [0, 15] 130 | nvif_outp_acquire_dp(struct nvif_outp *outp, u8 dpcd[DP_RECEIVER_CAP_SIZE], | ~~~^~~~~~~~~~~~~~~...

Now that we've extracted i915's code for reading both the normal DPCD caps and extended DPCD caps into a shared helper, let's start using this in nouveau to enable us to start checking extended DPCD caps for free. Signed-off-by: Lyude Paul <lyude at redhat.com> --- drivers/gpu/drm/nouveau/nouveau_dp.c | 14 ++++++-------- 1 file changed, 6 insertions(+),...

Hi all, I've frustrated myself the last few days yelling at our link training code. Comparing the i915 code to radeon and nouveau I've noticed the lack of a nice set of dp helper functions. So I've started to extract a few. There's lots more that we can do I think (link configuration selection, the i2c over aux retry stuff which diverges already between i915 and radeon, maybe

...ers/gpu/drm/nouveau/nouveau_dp.c index 2674f15..85eac85 100644 --- a/drivers/gpu/drm/nouveau/nouveau_dp.c +++ b/drivers/gpu/drm/nouveau/nouveau_dp.c @@ -62,6 +62,7 @@ nouveau_dp_detect(struct nouveau_encoder *nv_encoder) struct nouveau_drm *drm = nouveau_drm(dev); struct nvkm_i2c_aux *aux; u8 dpcd[8]; + u8 port_cap[DP_MAX_DOWNSTREAM_PORTS] = {}; int ret; aux = nv_encoder->aux; @@ -72,6 +73,14 @@ nouveau_dp_detect(struct nouveau_encoder *nv_encoder) if (ret) return ret; + if (dpcd[DP_DPCD_REV] > 0x10) { + ret = nvkm_rdaux(aux, DP_DOWNSTREAM_PORT_0, + port_cap, DP_MAX_D...