From patchwork Sat Sep 10 05:47:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Manivannan Sadhasivam X-Patchwork-Id: 12972390 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 35CDDC6FA82 for ; Sat, 10 Sep 2022 05:47:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229937AbiIJFrU (ORCPT ); Sat, 10 Sep 2022 01:47:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229925AbiIJFrT (ORCPT ); Sat, 10 Sep 2022 01:47:19 -0400 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9BB9AF0E8 for ; Fri, 9 Sep 2022 22:47:16 -0700 (PDT) Received: by mail-wm1-x334.google.com with SMTP id z14-20020a7bc7ce000000b003a5db0388a8so181307wmk.1 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=Ga236gH4849CNhe/c7owrgnGqiIwDNXPE2QeZ8+un/oBfGgCZGdZXoMMejw9XN1BP1 YMTZTW7fEuzxgdoraqYx2GGuYHw6UXBGrrFbdGFvxtjUWcPNqYE1Ihu4BPLzUbxRatK1 SyWOMXlU1fA1y3EfjbMtTrbOUsH3ICGEMUN2agDG5UtEoPSXD43X0QeOg0IyF/D0TKk4 pHL6hRobsJtPh36JJGVs3fodwp3g47Y5xTnhNZMyxNJD92iKvCotFJ7XA4fUWySbgPSa 5ksrm5aA+4UBwx0IBMcj4kdt9jPEn+TsqTpp60WRHjJ7OJZ9mEcADVeK+tZucH3/Ww0V nLQw== X-Gm-Message-State: ACgBeo2ZOy/edHIaP4xnVD8sYGaG7lwujRcAAqnwJLHYZzwD5mIikwpV +g87KZI/4SvtYLosuGSlwx6T 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 Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org 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-edma-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_chan *dchan) if (chan->status != EDMA_ST_IDLE) return -EBUSY; - pm_runtime_get(chan->dw->chip->dev); - return 0; } static void dw_edma_free_chan_resources(struct dma_chan *dchan) { unsigned long timeout = jiffies + msecs_to_jiffies(5000); - struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); int ret; while (time_before(jiffies, timeout)) { @@ -703,8 +699,6 @@ static void dw_edma_free_chan_resources(struct dma_chan *dchan) cpu_relax(); } - - pm_runtime_put(chan->dw->chip->dev); } 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; - /* Power management */ - pm_runtime_enable(dev); - /* Turn debugfs on */ dw_edma_v0_core_debugfs_on(dw); @@ -1009,9 +1000,6 @@ int dw_edma_remove(struct dw_edma_chip *chip) for (i = (dw->nr_irqs - 1); i >= 0; i--) free_irq(chip->ops->irq_vector(dev, i), &dw->irq[i]); - /* 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,