From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE319C433EF for ; Wed, 6 Oct 2021 04:26:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C47286120F for ; Wed, 6 Oct 2021 04:26:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230102AbhJFE2S (ORCPT ); Wed, 6 Oct 2021 00:28:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229627AbhJFE2Q (ORCPT ); Wed, 6 Oct 2021 00:28:16 -0400 Received: from mail-ot1-x32e.google.com (mail-ot1-x32e.google.com [IPv6:2607:f8b0:4864:20::32e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90A63C06174E for ; Tue, 5 Oct 2021 21:26:24 -0700 (PDT) Received: by mail-ot1-x32e.google.com with SMTP id u20-20020a9d7214000000b0054e170300adso1500228otj.13 for ; Tue, 05 Oct 2021 21:26:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:in-reply-to:references:from:user-agent:date:message-id :subject:to:cc; bh=lpo3jySHVpuECP223gucHzK6qPCa78lLyTG8fTbUCo0=; b=ThymPaq4pAQseP8pjGIzPhYU0jBZgINzCAXU+02yprRKuRVcVnntiVBge5fbOfF1RF W8kxfZqaNE8gFDoJPaGn802Vgto0JPchR2hb+G8Q5ANj+OaO6mji9CvK6kyTxeimq/TW b00JBCvRa9213DYDkviCzfF9Un4myvLxKzxB4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:in-reply-to:references:from :user-agent:date:message-id:subject:to:cc; bh=lpo3jySHVpuECP223gucHzK6qPCa78lLyTG8fTbUCo0=; b=R7RUugScW5IZH3bd66+3/37jTar5otUYLILyGPRdqNMvSIOduEfnrY4RSzxxAzyJaO pqq4Ib4rpLjDxoPqO6EIO7OfXCdiq276z6zwK4E9Lm63HCJCS3x8Xn+LJ1fYU4+Ehf/v TXcndXmlHfP356h1THx48aNprZmvcYjjzwtGKItPjbzw1NYpRt+DxRJ1+8FBGHOEeeyn Iq26OEpsGyaJRfkp4DrfNK+T5bnCsFabvKCJcaoR7sohCQ840cAV4aVEb21X1NEjObuK bd/cN9yL9dUCb3N3HPxvB9tE5/FDEAA17pq3ObYx9OsJeSaCYaflmBtfnW8nrhN2EMUo vWag== X-Gm-Message-State: AOAM5339Tq8WF90a5MoBp/73eubZMfZGddZoRp+UIBZDR2bza1SiBhqb hdIrs0Zfwj8ftZwshGv1AalvDdoDoFFjRxzB/x9q8Q== X-Google-Smtp-Source: ABdhPJyqbzfyuJgjhBaq32N9NwF+pauRq+8vq/c8zppXAuy0EqIE7jhu1C7daYuBbpWdAykWQtLHt93NS0DMt6rPzcA= X-Received: by 2002:a9d:6a0f:: with SMTP id g15mr18218054otn.126.1633494383457; Tue, 05 Oct 2021 21:26:23 -0700 (PDT) Received: from 753933720722 named unknown by gmailapi.google.com with HTTPREST; Tue, 5 Oct 2021 21:26:22 -0700 MIME-Version: 1.0 In-Reply-To: References: <20211005231323.2663520-1-bjorn.andersson@linaro.org> <20211005231323.2663520-6-bjorn.andersson@linaro.org> From: Stephen Boyd User-Agent: alot/0.9.1 Date: Tue, 5 Oct 2021 21:26:22 -0700 Message-ID: Subject: Re: [PATCH v4 5/7] drm/msm/dp: Support up to 3 DP controllers To: Bjorn Andersson Cc: Abhinav Kumar , Daniel Vetter , David Airlie , Dmitry Baryshkov , Kalyan Thota , Kuogee Hsieh , Rob Clark , Sean Paul , Rob Herring , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Maybe struct msm_dp_desc { phys_addr_t io_start; unsigned int id; }; and then have msm_dp_desc::id equal INTF_ and then look through the intf from DPU here in the DP driver to find the id and type of connector that should be used by default? Still sort of fragile because the only connection is an unsigned int which isn't great, but at least it's explicit instead of implicit based on the array order.