From nobody Wed Apr 8 12:51:09 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71C80C6FA83 for ; Sat, 10 Sep 2022 05:47:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229925AbiIJFrU (ORCPT ); Sat, 10 Sep 2022 01:47:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229529AbiIJFrS (ORCPT ); Sat, 10 Sep 2022 01:47:18 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB113AF0F4 for ; Fri, 9 Sep 2022 22:47:16 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id j26so3030341wms.0 for ; Fri, 09 Sep 2022 22:47:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date; bh=ZJI6ORqG8zxYZu2zKJ+oG09ScvKO2aVfOsuZsiN3680=; b=Tu4qy0kztYakM/miHZmmtYGaP6yE/1FKs+DVQGKEDmxX8KIBR+z+Y4HBEpDEkbovDx 8x03b0EGqV8EYTxYzSRizirJu4gKavtWL+KA9HlhPEC6bw+K+/KOUZVQEq088NMKmY+a 9gvwrRxw/Mru3kyFW1BpdhNM6hXBMbWM6GxM+7ll+wClmzQ25YGX3SX8v28s8xObPM2l Pidh/LTTzotago3eA1OPeh0cx+4F1RZOPFDD71+HT6XBuXaB4O2v0tKPfyfGf51ZF0u9 mKthTKE15winScuboCo0lS0rlb1nLwVtSIWxxiiVEk/3nEsw326teN7TV9LhJpfT2vam bAXw== 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; bh=ZJI6ORqG8zxYZu2zKJ+oG09ScvKO2aVfOsuZsiN3680=; b=BbfZAasUoILV0lqvLSB/A7/HulFWBc4GRVzi0ik+WPB/CWKU2RBo8RvrlZAu1Nx3yl vS9l4E4iGgz0+Z+3LgpitLrLDeomyThwA8rbYORYdofAPNpvspRsjudcOHGMe8ciKxSK ZwpaMOuyxPyh26Ik6aWHznAQbgoYazCngrFIVkS5hGCUNn1xS3+Es0COgP6BZni5gDaB RNAutTVX9QDRecZ8V84zMCVCXNZ62EXyAVWVQaC+ScLpeL26VbJelUAm1kk5jHdKFh3S wekd26pPLIHtCudwWJDxyj0F1GK32HMI9iEVv3W+I0stjSGPkY4MlRQYyh7drgDMMhKj nbRA== X-Gm-Message-State: ACgBeo1gd4PU8J60CyNGTRMITRJYTgVveeRf4jtv4pRGY0O3BNakAfSy FBYKBFY5xn8qDO0GDy2F26nh X-Google-Smtp-Source: AA6agR7ARJ5rUJ37hddKyqCD7uYAdH5V0KMU435NKXHX5xqcvZ5yr7uJS+/TIDXKb4GdrTCF/XJaGg== X-Received: by 2002:a1c:f20d:0:b0:3a8:4176:139b with SMTP id s13-20020a1cf20d000000b003a84176139bmr7109594wmc.177.1662788835406; Fri, 09 Sep 2022 22:47:15 -0700 (PDT) Received: from localhost.localdomain ([117.217.182.47]) by smtp.gmail.com with ESMTPSA id c4-20020adffb44000000b0022a2c600d5csm2031039wrs.55.2022.09.09.22.47.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Sep 2022 22:47:15 -0700 (PDT) From: Manivannan Sadhasivam To: gustavo.pimentel@synopsys.com, vkoul@kernel.org Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Manivannan Sadhasivam , Serge Semin , Frank Li Subject: [PATCH v2] dmaengine: dw-edma: Remove runtime PM support Date: Sat, 10 Sep 2022 11:17:00 +0530 Message-Id: <20220910054700.12205-1-manivannan.sadhasivam@linaro.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Currently, the dw-edma driver enables the runtime_pm for parent device (chip->dev) and increments/decrements the refcount during alloc/free chan resources callbacks. This leads to a problem when the eDMA driver has been probed, but the channels were not used. This scenario can happen when the DW PCIe driver probes eDMA driver successfully, but the PCI EPF driver decides not to use eDMA channels and use iATU instead for PCI transfers. In this case, the underlying device would be runtime suspended due to pm_runtime_enable() in dw_edma_probe() and the PCI EPF driver would have no knowledge of it. Ideally, the eDMA driver should not be the one doing the runtime PM of the parent device. The responsibility should instead belong to the client drivers like PCI EPF. So let's remove the runtime PM support from eDMA driver. Cc: Serge Semin Cc: Frank Li Reviewed-by: Serge Semin Signed-off-by: Manivannan Sadhasivam --- Changes in v2: - Added review tag from Sergey - Rebased on top of v6.0.0-rc1 drivers/dma/dw-edma/dw-edma-core.c | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-ed= ma-core.c index 07f756479663..c54b24ff5206 100644 --- a/drivers/dma/dw-edma/dw-edma-core.c +++ b/drivers/dma/dw-edma/dw-edma-core.c @@ -9,7 +9,6 @@ #include #include #include -#include #include #include #include @@ -682,15 +681,12 @@ static int dw_edma_alloc_chan_resources(struct dma_ch= an *dchan) if (chan->status !=3D EDMA_ST_IDLE) return -EBUSY; =20 - pm_runtime_get(chan->dw->chip->dev); - return 0; } =20 static void dw_edma_free_chan_resources(struct dma_chan *dchan) { unsigned long timeout =3D jiffies + msecs_to_jiffies(5000); - struct dw_edma_chan *chan =3D dchan2dw_edma_chan(dchan); int ret; =20 while (time_before(jiffies, timeout)) { @@ -703,8 +699,6 @@ static void dw_edma_free_chan_resources(struct dma_chan= *dchan) =20 cpu_relax(); } - - pm_runtime_put(chan->dw->chip->dev); } =20 static int dw_edma_channel_setup(struct dw_edma *dw, bool write, @@ -977,9 +971,6 @@ int dw_edma_probe(struct dw_edma_chip *chip) if (err) goto err_irq_free; =20 - /* Power management */ - pm_runtime_enable(dev); - /* Turn debugfs on */ dw_edma_v0_core_debugfs_on(dw); =20 @@ -1009,9 +1000,6 @@ int dw_edma_remove(struct dw_edma_chip *chip) for (i =3D (dw->nr_irqs - 1); i >=3D 0; i--) free_irq(chip->ops->irq_vector(dev, i), &dw->irq[i]); =20 - /* Power management */ - pm_runtime_disable(dev); - /* Deregister eDMA device */ dma_async_device_unregister(&dw->wr_edma); list_for_each_entry_safe(chan, _chan, &dw->wr_edma.channels, --=20 2.25.1