Hi, On Wed, 6 Oct 2021 at 10:06, Stephen Boyd <swb...@chromium.org> wrote: > > Quoting Dmitry Baryshkov (2021-10-05 23:10:22) > > On Wed, 6 Oct 2021 at 07:26, Stephen Boyd <swb...@chromium.org> wrote: > > > > > > Quoting Bjorn Andersson (2021-10-05 19:37:52) > > > > On Tue 05 Oct 19:06 PDT 2021, Stephen Boyd wrote: > > > > > > > > > Quoting Bjorn Andersson (2021-10-05 18:43:16) > > > > > > On Tue 05 Oct 17:43 PDT 2021, Stephen Boyd wrote: > > > > > > > > > > > > > Quoting Bjorn Andersson (2021-10-05 16:13:21) > > > > > > > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c > > > > > > > > b/drivers/gpu/drm/msm/dp/dp_display.c > > > > > > > > index bdaf227f05dc..674cddfee5b0 100644 > > > > > > > > --- a/drivers/gpu/drm/msm/dp/dp_display.c > > > > > > > > +++ b/drivers/gpu/drm/msm/dp/dp_display.c > > > > > > > > @@ -1233,7 +1239,7 @@ static int dp_display_probe(struct > > > > > > > > platform_device *pdev) > > > > > > > > if (!dp) > > > > > > > > return -ENOMEM; > > > > > > > > > > > > > > > > - desc = dp_display_get_desc(pdev); > > > > > > > > + desc = dp_display_get_desc(pdev, &dp->id); > > > > > > > > > > > > > > I'm sad that dp->id has to match the number in the SoC specific > > > > > > > dpu_intf_cfg array in > > > > > > > drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c > > > > > > > still. Is there any way we can avoid that? Also, notice how those > > > > > > > arrays > > > > > > > already have INTF_DP macros, which makes me think that it may be > > > > > > > better > > > > > > > to connect this to those arrays instead of making an msm_dp_desc > > > > > > > structure and then make sure the 'type' member matches a connector > > > > > > > type number. Otherwise this code is super fragile. > > > > > > > > > > > > > > > > > > > I'm afraid I don't understand what you're proposing. Or which part > > > > > > you > > > > > > consider fragile, the indices of the INTF_DP instances aren't going > > > > > > to > > > > > > move around... > > > > > > > > > > > > I have N instances of the DP driver that I need to match to N > > > > > > entries > > > > > > from the platform specific intf array, I need some stable reference > > > > > > between them. When I started this journey I figured I could rely on > > > > > > the > > > > > > of_graph between the DPU and the interface controllers, but the > > > > > > values > > > > > > used there today are just bogus, so that was a no go. > > > > > > > > > > > > We can use whatever, as long as _dpu_kms_initialize_displayport() > > > > > > can > > > > > > come up with an identifier to put in h_tile_instance[0] so that > > > > > > dpu_encoder_setup_display() can find the relevant INTF. > > > > > > > > > > > > > > > > To make it more concrete we can look at sc7180 > > > > > > > > > > static const struct dpu_intf_cfg sc7180_intf[] = { > > > > > INTF_BLK("intf_0", INTF_0, 0x6A000, INTF_DP, 0, 24, > > > > > INTF_SC7180_MASK, MDP_SSPP_TOP0_INTR, 24, 25), > > > > > ^ > > > > > | > > > > > > > > > > intf0 is irrelevant. Also the address is irrelevant. But here we have > > > > > a > > > > > zero, the number after INTF_DP, and that is very relevant. That number > > > > > needs to match the dp->id. Somewhere we have a match between > > > > > controller_id and dp->id in the code. > > > > > > > > That number (the 0, not INTF_0) is what the code matches against dp->id > > > > in _dpu_kms_initialize_displayport(), in order to figure out that this > > > > is INTF_0 in dpu_encoder_setup_display(). > > > > > > > > I.e. look at the sc8180x patch: > > > > > > > > INTF_BLK("intf_0", INTF_0, 0x6A000, INTF_DP, 0, 24, INTF_SC8180X_MASK, > > > > MDP_SSPP_TOP0_INTR, 24, 25), > > > > INTF_BLK("intf_1", INTF_1, 0x6A800, INTF_DSI, 0, 24, INTF_SC8180X_MASK, > > > > MDP_SSPP_TOP0_INTR, 26, 27), > > > > INTF_BLK("intf_2", INTF_2, 0x6B000, INTF_DSI, 1, 24, INTF_SC8180X_MASK, > > > > MDP_SSPP_TOP0_INTR, 28, 29), > > > > /* INTF_3 is for MST, wired to INTF_DP 0 and 1, use dummy index until > > > > this is supported */ > > > > INTF_BLK("intf_3", INTF_3, 0x6B800, INTF_DP, 999, 24, > > > > INTF_SC8180X_MASK, MDP_SSPP_TOP0_INTR, 30, 31), > > > > INTF_BLK("intf_4", INTF_4, 0x6C000, INTF_DP, 1, 24, INTF_SC8180X_MASK, > > > > MDP_SSPP_TOP0_INTR, 20, 21), > > > > INTF_BLK("intf_5", INTF_5, 0x6C800, INTF_DP, 2, 24, INTF_SC8180X_MASK, > > > > MDP_SSPP_TOP0_INTR, 22, 23), > > > > > > > > Where the DP driver defines the 3 controllers with dp->id of 0, 1 and 2, > > > > which the DPU code will match against to INTF_0, INTF_4 and INTF_5. > > > > > > > > > > Yep. I'm saying that having to make that number in this intf array match > > > the order of the register mapping descriptor array is fragile. Why can't > > > we indicate the interface is DP or eDP with INTF_DP or INTF_EDP and then > > > map from the descriptor array to this intf array somehow so that the > > > order of the descriptor array doesn't matter? Then we don't have to put > > > the connector type in the descriptor array, and we don't have to keep > > > the order of the array a certain way to match this intf descriptor. > > > > The order of the descriptor array does not matter currently (or we do > > not understand fully your concern). > > The encoder is mapped to intf using type + controller_id (next field > > after INTF_foo). > > Also having the controller_id in the descs array allows us to simplify > > DSI code (where DSI_0 is master and DSI_1 is slave, no matter which > > INTF they are associated with). > > The order seems to matter for me. Otherwise I get various vblank > timeouts and the eDP panel doesn't light up. I'm using the previous > version of this patch series though so maybe something got fixed in the > meantime. If I change the controller_id to match my new ordering of the > descriptor array then it works again. So somehow controller_id needs to > match dp->id?
Yes, controller_id should match. However the order of entries in the array should not matter. If it does, it's clearly an issue somewhere. > > > > > Last, but not least, maybe I'd point you to one of the proposed > > cleanup patches: > > https://lore.kernel.org/linux-arm-msm/20210515225757.1989955-5-dmitry.barysh...@linaro.org/ > > It removes one extra level of indirection in interface association. > > > > Thanks for the link. -- With best wishes Dmitry