From patchwork Thu Jan 19 22:53:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 46051 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp588895wrn; Thu, 19 Jan 2023 15:05:48 -0800 (PST) X-Google-Smtp-Source: AMrXdXtbxvFbdRwwETNyrdtJQGP7ZDVkZkPfTwhac6GPHJ8Clfr0PkzgeRAPmuEsTdakgUacjYRz X-Received: by 2002:a62:bd08:0:b0:58b:c3b3:d3dd with SMTP id a8-20020a62bd08000000b0058bc3b3d3ddmr12701029pff.21.1674169547745; Thu, 19 Jan 2023 15:05:47 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674169547; cv=none; d=google.com; s=arc-20160816; b=E9bATa/SkOoiRzCZlkDiHcGoZaLahpNVyGwPCRpHHygK0vOvMo5VhRd5qYfPfQRGB7 HSkIszPGqasJYiA3rVSGTL9MdcjuoghDl40Vx0PSx4M8OpbXWPY5wXWF5Hgc2LTPbooV RDftCtQs09Il07BSyPbObg5PH67DdFGH3ctyOPTODGHXFEbe0v6jXEn/J6aK6/y2LVIh A74DPfcv0ybhwzaYsqA7cBfrPhwdlSgsnhpXO5SWQDhh5209gSJ6+ZrzjD50rtTejA9g 24TVZcsevQMM/X9GGV+E0mDAeVNWFzkWLyR8pQ8LZaKd+99GtMI1zSSH4o97QR5jWEVV frFQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=zK3flFM0os1/8RqnL1ay80xg11/2BKbjIWxrUwGK7M4=; b=S6EaAQfogbOHQRpETQ9IGM++h5/rfwUG5BQkUXYQ0gj+s4P1UyR2TU4P43ENQxj6RM y2WTQAPWpJCKIUit33q4TY8uPiRRRZGOfKP7PkObDd76e/WHDfDF2SYPE6u7l8bZbJLf zdNAyEEedXOnR68OuB3frckHXg4JHRmoa+uqHVFIaLa+STyOPF26ducZs/oILkl/Bp9f Hho1veyASkZHUnoSrHM0WhsEBw2Sw2f1oIodiKmvSXF7hPULZzATab4ZUMsi0QpyR+Pg pNw/D3NRhTxBQlH1HhMa+ZVSsrL7OyxwdGt/V5RdhQvlzVsaxD5Ph0pRTLkMmHp2/ZJw er8A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=l0YGmDqm; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id a20-20020a621a14000000b0058da3eef4c4si13515661pfa.181.2023.01.19.15.05.34; Thu, 19 Jan 2023 15:05:47 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=l0YGmDqm; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230511AbjASXDW (ORCPT + 99 others); Thu, 19 Jan 2023 18:03:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230499AbjASXCf (ORCPT ); Thu, 19 Jan 2023 18:02:35 -0500 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C794CA7910 for ; Thu, 19 Jan 2023 14:54:16 -0800 (PST) Received: by mail-pf1-x42c.google.com with SMTP id z3so2692004pfb.2 for ; Thu, 19 Jan 2023 14:54:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=zK3flFM0os1/8RqnL1ay80xg11/2BKbjIWxrUwGK7M4=; b=l0YGmDqm5C5ZhFisPOG8kWvvPg+hny4gYE6MbwBI5yi73o/1HpUgvAkTv3j8dXpYM9 Ixm8iUPoPa5UcQsX1xWPU7Wz5THBMvuryxFUyyxvYbi0XpOEYsvBiz50xR7FTsw1AFqk cNqikGYSy1tbV2U/r6xCg6bFxTUznjMcXY7Rg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=zK3flFM0os1/8RqnL1ay80xg11/2BKbjIWxrUwGK7M4=; b=tz6fiBoFWNjASA76uxW2f18aX+xpNtUdL4bIyUUs0GPtyp0TZEfiR8NwxYWlY6I5r0 0DXdt1AnwWnFEjwRKv2ElKXDyLiLwc8Yt94cSUeb2rvPDgUPZx1qdkmUymVx4m2ebRhR GZgbLdX15gFkLaHjAGEi64G/VNuF53wpAKHg9xAwwVP92agWrcF2K4TYpWlfvZlv7N0c BRyunlI6TmU9nTuL7m2dE8h060IUBzsm/TcsFQrWQXb5RfZG1plHC2RfcckZ4sICFxjX tQtCGHz55eSfGaryu+nDZRe6tEWHLOfqgo5Yw5s64EbZAe2CuhX5JwBtXNuVSZl8v4JU FJDw== X-Gm-Message-State: AFqh2koxw2JU1DEjXcxTr8MtQDrX4cMZVCeu6zbXVjwkAQRSDyNx6Sh3 0y+cfn+X4OidHkCub7vNqy0jgQ== X-Received: by 2002:a05:6a00:1585:b0:578:8864:b25c with SMTP id u5-20020a056a00158500b005788864b25cmr16151179pfk.25.1674168856101; Thu, 19 Jan 2023 14:54:16 -0800 (PST) Received: from tictac2.mtv.corp.google.com ([2620:15c:9d:2:62c2:e2e0:4fda:849e]) by smtp.gmail.com with ESMTPSA id f127-20020a623885000000b00588cb819473sm20198839pfa.39.2023.01.19.14.54.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Jan 2023 14:54:15 -0800 (PST) From: Douglas Anderson To: Rob Clark , Abhinav Kumar , Dmitry Baryshkov Cc: Kuogee Hsieh , Stephen Boyd , Douglas Anderson , Daniel Vetter , David Airlie , Sankeerth Billakanti , Sean Paul , Thomas Zimmermann , dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] drm/msm/dp: Clean up handling of DP AUX interrupts Date: Thu, 19 Jan 2023 14:53:42 -0800 Message-Id: <20230119145248.1.I90ffed3ddd21e818ae534f820cb4d6d8638859ab@changeid> X-Mailer: git-send-email 2.39.0.246.g2a6d74b583-goog MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1755494007463479008?= X-GMAIL-MSGID: =?utf-8?q?1755494007463479008?= The DP AUX interrupt handling was a bit of a mess. * There were two functions (one for "native" transfers and one for "i2c" transfers) that were quite similar. It was hard to say how many of the differences between the two functions were on purpose and how many of them were just an accident of how they were coded. * Each function sometimes used "else if" to test for error bits and sometimes didn't and again it was hard to say if this was on purpose or just an accident. * The two functions wouldn't notice whether "unknown" bits were set. For instance, there seems to be a bit "DP_INTR_PLL_UNLOCKED" and if it was set there would be no indication. * The two functions wouldn't notice if more than one error was set. Let's fix this by being more consistent / explicit about what we're doing. By design this could cause different handling for AUX transfers, though I'm not actually aware of any bug fixed as a result of this patch (this patch was created because we simply noticed how odd the old code was by code inspection). Specific notes here: 1. In the old native transfer case if we got "done + wrong address" we'd ignore the "wrong address" (because of the "else if"). Now we won't. 2. In the old native transfer case if we got "done + timeout" we'd ignore the "timeout" (because of the "else if"). Now we won't. 3. In the old native transfer case we'd see "nack_defer" and translate it to the error number for "nack". This differed from the i2c transfer case where "nack_defer" was given the error number for "nack_defer". This 100% can't matter because the only user of this error number treats "nack defer" the same as "nack", so it's clear that the difference between the "native" and "i2c" was pointless here. 4. In the old i2c transfer case if we got "done" plus any error besides "nack" or "defer" then we'd ignore the error. Now we don't. 5. If there is more than one error signaled by the hardware it's possible that we'll report a different one than we used to. I don't know if this matters. If someone is aware of a case this matters we should document it and change the code to make it explicit. 6. One quirk we keep (I don't know if this is important) is that in the i2c transfer case if we see "done + defer" we report that as a "nack". That seemed too intentional in the old code to just drop. After this change we will add extra logging, including: * A warning if we see more than one error bit set. * A warning if we see an unexpected interrupt. * A warning if we get an AUX transfer interrupt when shouldn't. It actually turns out that as a result of this change then at boot we sometimes see an error: [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy That means that, during init, we are seeing DP_INTR_PLL_UNLOCKED. For now I'm going to say that leaving this error reported in the logs is OK-ish and hopefully it will encourage someone to track down what's going on at init time. One last note here is that this change renames one of the interrupt bits. The bit named "i2c done" clearly was used for native transfers being done too, so I renamed it to indicate this. Signed-off-by: Douglas Anderson --- I don't have good test coverage for this change and it does have the potential to change behavior. I confirmed that eDP and DP still continue to work OK on one machine. Hopefully folks can test it more. drivers/gpu/drm/msm/dp/dp_aux.c | 80 ++++++++++++----------------- drivers/gpu/drm/msm/dp/dp_catalog.c | 2 +- drivers/gpu/drm/msm/dp/dp_catalog.h | 2 +- 3 files changed, 36 insertions(+), 48 deletions(-) diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c index cc3efed593aa..34ad08ae6eb9 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.c +++ b/drivers/gpu/drm/msm/dp/dp_aux.c @@ -162,47 +162,6 @@ static ssize_t dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, return i; } -static void dp_aux_native_handler(struct dp_aux_private *aux, u32 isr) -{ - if (isr & DP_INTR_AUX_I2C_DONE) - aux->aux_error_num = DP_AUX_ERR_NONE; - else if (isr & DP_INTR_WRONG_ADDR) - aux->aux_error_num = DP_AUX_ERR_ADDR; - else if (isr & DP_INTR_TIMEOUT) - aux->aux_error_num = DP_AUX_ERR_TOUT; - if (isr & DP_INTR_NACK_DEFER) - aux->aux_error_num = DP_AUX_ERR_NACK; - if (isr & DP_INTR_AUX_ERROR) { - aux->aux_error_num = DP_AUX_ERR_PHY; - dp_catalog_aux_clear_hw_interrupts(aux->catalog); - } -} - -static void dp_aux_i2c_handler(struct dp_aux_private *aux, u32 isr) -{ - if (isr & DP_INTR_AUX_I2C_DONE) { - if (isr & (DP_INTR_I2C_NACK | DP_INTR_I2C_DEFER)) - aux->aux_error_num = DP_AUX_ERR_NACK; - else - aux->aux_error_num = DP_AUX_ERR_NONE; - } else { - if (isr & DP_INTR_WRONG_ADDR) - aux->aux_error_num = DP_AUX_ERR_ADDR; - else if (isr & DP_INTR_TIMEOUT) - aux->aux_error_num = DP_AUX_ERR_TOUT; - if (isr & DP_INTR_NACK_DEFER) - aux->aux_error_num = DP_AUX_ERR_NACK_DEFER; - if (isr & DP_INTR_I2C_NACK) - aux->aux_error_num = DP_AUX_ERR_NACK; - if (isr & DP_INTR_I2C_DEFER) - aux->aux_error_num = DP_AUX_ERR_DEFER; - if (isr & DP_INTR_AUX_ERROR) { - aux->aux_error_num = DP_AUX_ERR_PHY; - dp_catalog_aux_clear_hw_interrupts(aux->catalog); - } - } -} - static void dp_aux_update_offset_and_segment(struct dp_aux_private *aux, struct drm_dp_aux_msg *input_msg) { @@ -427,13 +386,42 @@ void dp_aux_isr(struct drm_dp_aux *dp_aux) if (!isr) return; - if (!aux->cmd_busy) + if (!aux->cmd_busy) { + DRM_ERROR("Unexpected DP AUX IRQ %#010x when not busy\n", isr); return; + } - if (aux->native) - dp_aux_native_handler(aux, isr); - else - dp_aux_i2c_handler(aux, isr); + /* + * The logic below assumes only one error bit is set (other than "done" + * which can apparently be set at the same time as some of the other + * bits). Warn if more than one get set so we know we need to improve + * the logic. + */ + if (hweight32(isr & ~DP_INTR_AUX_XFER_DONE) > 1) + DRM_WARN("Some DP AUX interrupts unhandled: %#010x\n", isr); + + if (isr & DP_INTR_AUX_ERROR) { + aux->aux_error_num = DP_AUX_ERR_PHY; + dp_catalog_aux_clear_hw_interrupts(aux->catalog); + } else if (isr & DP_INTR_NACK_DEFER) { + aux->aux_error_num = DP_AUX_ERR_NACK_DEFER; + } else if (isr & DP_INTR_WRONG_ADDR) { + aux->aux_error_num = DP_AUX_ERR_ADDR; + } else if (isr & DP_INTR_TIMEOUT) { + aux->aux_error_num = DP_AUX_ERR_TOUT; + } else if (isr & DP_INTR_AUX_XFER_DONE) { + aux->aux_error_num = DP_AUX_ERR_NONE; + } else if (!aux->native && (isr & DP_INTR_I2C_NACK)) { + aux->aux_error_num = DP_AUX_ERR_NACK; + } else if (!aux->native && (isr & DP_INTR_I2C_DEFER)) { + if (isr & DP_INTR_AUX_XFER_DONE) + aux->aux_error_num = DP_AUX_ERR_NACK; + else + aux->aux_error_num = DP_AUX_ERR_DEFER; + } else { + DRM_WARN("Unexpected interrupt: %#010x\n", isr); + return; + } complete(&aux->comp); } diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c index 676279d0ca8d..421391755427 100644 --- a/drivers/gpu/drm/msm/dp/dp_catalog.c +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c @@ -27,7 +27,7 @@ #define DP_INTF_CONFIG_DATABUS_WIDEN BIT(4) #define DP_INTERRUPT_STATUS1 \ - (DP_INTR_AUX_I2C_DONE| \ + (DP_INTR_AUX_XFER_DONE| \ DP_INTR_WRONG_ADDR | DP_INTR_TIMEOUT | \ DP_INTR_NACK_DEFER | DP_INTR_WRONG_DATA_CNT | \ DP_INTR_I2C_NACK | DP_INTR_I2C_DEFER | \ diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h index 1f717f45c115..f36b7b372a06 100644 --- a/drivers/gpu/drm/msm/dp/dp_catalog.h +++ b/drivers/gpu/drm/msm/dp/dp_catalog.h @@ -13,7 +13,7 @@ /* interrupts */ #define DP_INTR_HPD BIT(0) -#define DP_INTR_AUX_I2C_DONE BIT(3) +#define DP_INTR_AUX_XFER_DONE BIT(3) #define DP_INTR_WRONG_ADDR BIT(6) #define DP_INTR_TIMEOUT BIT(9) #define DP_INTR_NACK_DEFER BIT(12) From patchwork Thu Jan 19 22:53:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 46052 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp592878wrn; Thu, 19 Jan 2023 15:14:43 -0800 (PST) X-Google-Smtp-Source: AMrXdXtbF+8ngKcvnR1PyzbDV5yDr2P2XpYmScv4drP1yiVbxS1LsOvuZD2PO3F+m+tu2kVcndOj X-Received: by 2002:a17:907:2106:b0:7c1:32:3574 with SMTP id qn6-20020a170907210600b007c100323574mr14748740ejb.12.1674170082894; Thu, 19 Jan 2023 15:14:42 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674170082; cv=none; d=google.com; s=arc-20160816; b=DD8R89pvOtzMKavwM/Jd7r4t9QWtRBPRq6Oc9vZVpgFITzvtnwTf55nEFkcHizfDqG 8CtUxotx6SQPPOm1TAWDGNjBBvYGsVIGZqd8Z7GQGDgm47SM6UD8j1jr34EFQgvi0RnR RR/kX7VmJx2kozT2UZzkt8nTZuCuz4ds+U/F2gs319c4PIgfBdTd1tASzEA0z0sObw56 cIL68o3w7c5exLoRyQu5vzCgBVr4/MIo7bRExrvEwJsajHbj5lBdnfIuzjaMh7KxEDdP jCOqhmqTYA/d9LZRA1cjTjnr311mH5gvnjoJQ36DzJkakIyK+TWGfCtHAcK/mlnDuEAc Dyew== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=bV+jI6lHrlyCpT8hI1E9uFmq1lCM9hqs/OL2V3boQaE=; b=FAWIvRK3/0tLenUAg3ijqd9siF0IOCPfenQVLQdoZeH40aIIcu48/Kc18rJ2YjM2hT V0GIy+qgDxn1r9U5Jo5iLdEfIUdnMWXPDtYW+jJRbz4KQ4kjViOf/Uin7c2cmj/Ye/ZU xsL/BTc28E3F+Ur0Lg/e7jsLvnFGhClxOLsKyG5XaE6Cr5KUprHjGIZJmfc/2ipZybU6 kva5w0hG89d5Y50Dpc4g1wAxzIKoUaQ3peUfaI60X04henwPiUMhsx2Wu8pyLN/pJCoP Al19Y6rLFIbMW8kVPNKFTmBs0RWdSDuuukL4mEvdnXhNvtEhRgW6H2ulOlhqsg3tnowX 2mrA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=Ts36WXoe; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id ne10-20020a1709077b8a00b007c170f6b32dsi27027745ejc.516.2023.01.19.15.14.16; Thu, 19 Jan 2023 15:14:42 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=Ts36WXoe; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231152AbjASXDb (ORCPT + 99 others); Thu, 19 Jan 2023 18:03:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230504AbjASXCg (ORCPT ); Thu, 19 Jan 2023 18:02:36 -0500 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C9D7A793D for ; Thu, 19 Jan 2023 14:54:18 -0800 (PST) Received: by mail-pg1-x536.google.com with SMTP id 78so2786620pgb.8 for ; Thu, 19 Jan 2023 14:54:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=bV+jI6lHrlyCpT8hI1E9uFmq1lCM9hqs/OL2V3boQaE=; b=Ts36WXoetdK/kuBnP/3bXmmdbice3lQOwq3KgC9YMZHHh/9bkWvWiXXpyOGqTkrVbP JP8odoCRTIdWVSkyw56A7sEYaCd0wKdER9uukA02FiVT3duIzNC+NiRYEHwHckIFGc6K jcte3cW3B8HAcsGWK3pu8Uz8b0MsOQ7HjIzk0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=bV+jI6lHrlyCpT8hI1E9uFmq1lCM9hqs/OL2V3boQaE=; b=orz5z9we6b0AVgDCVTX30dfaxuypYRbPUH3/GhhZUKgmGv61sZuUIedqlJL+SRks5+ Q/+ySAt9NBoY3niYlDDJGr7tcqrnHmm0N1e+yxBL/KI39fVLt46eLgpZm0cbFarR7HvM ObZwJiVYNTsgR5cBGctW7okwqRXGc2t2HKKFThowz2eAl8JN1s9MkVaBAYCVLdjCuOcE 5J5g43C9HzH3dPJhw8wyMkwdb1c0FTW7UIa8WtLwer7u1tzVo/S6nSDbuU/xQD+jFZbC xdt+nY1U+tszqt0gCSvaxBOWARdeul/TXL2M7Xm9Ly5dMSkBHl1Cw6fgLEYV+2mxaPCL bqqw== X-Gm-Message-State: AFqh2kqANS2wq1Xo6eoqnNFjcPJ4I1mqbngnkBa6TihJChfZm1Q975xg muE+QnKwk/4JsUxW5zylz+s4ig== X-Received: by 2002:aa7:96f7:0:b0:582:5b8d:52be with SMTP id i23-20020aa796f7000000b005825b8d52bemr13909854pfq.8.1674168857972; Thu, 19 Jan 2023 14:54:17 -0800 (PST) Received: from tictac2.mtv.corp.google.com ([2620:15c:9d:2:62c2:e2e0:4fda:849e]) by smtp.gmail.com with ESMTPSA id f127-20020a623885000000b00588cb819473sm20198839pfa.39.2023.01.19.14.54.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Jan 2023 14:54:17 -0800 (PST) From: Douglas Anderson To: Rob Clark , Abhinav Kumar , Dmitry Baryshkov Cc: Kuogee Hsieh , Stephen Boyd , Douglas Anderson , Bjorn Andersson , Daniel Vetter , David Airlie , Javier Martinez Canillas , Johan Hovold , Sankeerth Billakanti , Sean Paul , Thomas Zimmermann , dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] drm/msm/dp: Return IRQ_NONE for unhandled interrupts Date: Thu, 19 Jan 2023 14:53:43 -0800 Message-Id: <20230119145248.2.I2d7aec2fadb9c237cd0090a47d6a8ba2054bf0f8@changeid> X-Mailer: git-send-email 2.39.0.246.g2a6d74b583-goog In-Reply-To: <20230119145248.1.I90ffed3ddd21e818ae534f820cb4d6d8638859ab@changeid> References: <20230119145248.1.I90ffed3ddd21e818ae534f820cb4d6d8638859ab@changeid> MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1755494568859584949?= X-GMAIL-MSGID: =?utf-8?q?1755494568859584949?= If our interrupt handler gets called and we don't really handle the interrupt then we should return IRQ_NONE. The current interrupt handler didn't do this, so let's fix it. NOTE: for some of the cases it's clear that we should return IRQ_NONE and some cases it's clear that we should return IRQ_HANDLED. However, there are a few that fall somewhere in between. Specifically, the documentation for when to return IRQ_NONE vs. IRQ_HANDLED is probably best spelled out in the commit message of commit d9e4ad5badf4 ("Document that IRQ_NONE should be returned when IRQ not actually handled"). That commit makes it clear that we should return IRQ_HANDLED if we've done something to make the interrupt stop happening. The case where it's unclear is, for instance, in dp_aux_isr() after we've read the interrupt using dp_catalog_aux_get_irq() and confirmed that "isr" is non-zero. The function dp_catalog_aux_get_irq() not only reads the interrupts but it also "ack"s all the interrupts that are returned. For an "unknown" interrupt this has a very good chance of actually stopping the interrupt from happening. That would mean we've identified that it's our device and done something to stop them from happening and should return IRQ_HANDLED. Specifically, it should be noted that most interrupts that need "ack"ing are ones that are one-time events and doing an "ack" is enough to clear them. However, since these interrupts are unknown then, by definition, it's unknown if "ack"ing them is truly enough to clear them. It's possible that we also need to remove the original source of the interrupt. In this case, IRQ_NONE would be a better choice. Given that returning an occasional IRQ_NONE isn't the absolute end of the world, however, let's choose that course of action. The IRQ framework will forgive a few IRQ_NONE returns now and again (and it won't even log them, which is why we have to log them ourselves). This means that if we _do_ end hitting an interrupt where "ack"ing isn't enough the kernel will eventually detect the problem and shut our device down. Signed-off-by: Douglas Anderson --- drivers/gpu/drm/msm/dp/dp_aux.c | 12 +++++++----- drivers/gpu/drm/msm/dp/dp_aux.h | 2 +- drivers/gpu/drm/msm/dp/dp_ctrl.c | 10 ++++++++-- drivers/gpu/drm/msm/dp/dp_ctrl.h | 2 +- drivers/gpu/drm/msm/dp/dp_display.c | 8 +++++--- 5 files changed, 22 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c index 34ad08ae6eb9..59e323b7499d 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.c +++ b/drivers/gpu/drm/msm/dp/dp_aux.c @@ -368,14 +368,14 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux, return ret; } -void dp_aux_isr(struct drm_dp_aux *dp_aux) +irqreturn_t dp_aux_isr(struct drm_dp_aux *dp_aux) { u32 isr; struct dp_aux_private *aux; if (!dp_aux) { DRM_ERROR("invalid input\n"); - return; + return IRQ_NONE; } aux = container_of(dp_aux, struct dp_aux_private, dp_aux); @@ -384,11 +384,11 @@ void dp_aux_isr(struct drm_dp_aux *dp_aux) /* no interrupts pending, return immediately */ if (!isr) - return; + return IRQ_NONE; if (!aux->cmd_busy) { DRM_ERROR("Unexpected DP AUX IRQ %#010x when not busy\n", isr); - return; + return IRQ_NONE; } /* @@ -420,10 +420,12 @@ void dp_aux_isr(struct drm_dp_aux *dp_aux) aux->aux_error_num = DP_AUX_ERR_DEFER; } else { DRM_WARN("Unexpected interrupt: %#010x\n", isr); - return; + return IRQ_NONE; } complete(&aux->comp); + + return IRQ_HANDLED; } void dp_aux_reconfig(struct drm_dp_aux *dp_aux) diff --git a/drivers/gpu/drm/msm/dp/dp_aux.h b/drivers/gpu/drm/msm/dp/dp_aux.h index e930974bcb5b..511305da4f66 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.h +++ b/drivers/gpu/drm/msm/dp/dp_aux.h @@ -11,7 +11,7 @@ int dp_aux_register(struct drm_dp_aux *dp_aux); void dp_aux_unregister(struct drm_dp_aux *dp_aux); -void dp_aux_isr(struct drm_dp_aux *dp_aux); +irqreturn_t dp_aux_isr(struct drm_dp_aux *dp_aux); void dp_aux_init(struct drm_dp_aux *dp_aux); void dp_aux_deinit(struct drm_dp_aux *dp_aux); void dp_aux_reconfig(struct drm_dp_aux *dp_aux); diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index dd26ca651a05..1a5377ef1967 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1979,27 +1979,33 @@ int dp_ctrl_off(struct dp_ctrl *dp_ctrl) return ret; } -void dp_ctrl_isr(struct dp_ctrl *dp_ctrl) +irqreturn_t dp_ctrl_isr(struct dp_ctrl *dp_ctrl) { struct dp_ctrl_private *ctrl; u32 isr; + irqreturn_t ret = IRQ_NONE; if (!dp_ctrl) - return; + return IRQ_NONE; ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl); isr = dp_catalog_ctrl_get_interrupt(ctrl->catalog); + if (isr & DP_CTRL_INTR_READY_FOR_VIDEO) { drm_dbg_dp(ctrl->drm_dev, "dp_video_ready\n"); complete(&ctrl->video_comp); + ret = IRQ_HANDLED; } if (isr & DP_CTRL_INTR_IDLE_PATTERN_SENT) { drm_dbg_dp(ctrl->drm_dev, "idle_patterns_sent\n"); complete(&ctrl->idle_comp); + ret = IRQ_HANDLED; } + + return ret; } struct dp_ctrl *dp_ctrl_get(struct device *dev, struct dp_link *link, diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.h b/drivers/gpu/drm/msm/dp/dp_ctrl.h index 9f29734af81c..c3af06dc87b1 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.h +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.h @@ -25,7 +25,7 @@ int dp_ctrl_off_link_stream(struct dp_ctrl *dp_ctrl); int dp_ctrl_off_link(struct dp_ctrl *dp_ctrl); int dp_ctrl_off(struct dp_ctrl *dp_ctrl); void dp_ctrl_push_idle(struct dp_ctrl *dp_ctrl); -void dp_ctrl_isr(struct dp_ctrl *dp_ctrl); +irqreturn_t dp_ctrl_isr(struct dp_ctrl *dp_ctrl); void dp_ctrl_handle_sink_request(struct dp_ctrl *dp_ctrl); struct dp_ctrl *dp_ctrl_get(struct device *dev, struct dp_link *link, struct dp_panel *panel, struct drm_dp_aux *aux, diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 7ff60e5ff325..8996adbc5bd3 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -1192,7 +1192,7 @@ static int dp_hpd_event_thread_start(struct dp_display_private *dp_priv) static irqreturn_t dp_display_irq_handler(int irq, void *dev_id) { struct dp_display_private *dp = dev_id; - irqreturn_t ret = IRQ_HANDLED; + irqreturn_t ret = IRQ_NONE; u32 hpd_isr_status; if (!dp) { @@ -1220,13 +1220,15 @@ static irqreturn_t dp_display_irq_handler(int irq, void *dev_id) if (hpd_isr_status & DP_DP_HPD_UNPLUG_INT_MASK) dp_add_event(dp, EV_HPD_UNPLUG_INT, 0, 0); + + ret = IRQ_HANDLED; } /* DP controller isr */ - dp_ctrl_isr(dp->ctrl); + ret |= dp_ctrl_isr(dp->ctrl); /* DP aux isr */ - dp_aux_isr(dp->aux); + ret |= dp_aux_isr(dp->aux); return ret; }