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 X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58D57C04FE3 for ; Tue, 10 Aug 2021 14:22:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CF0F60F41 for ; Tue, 10 Aug 2021 14:22:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241539AbhHJOWg (ORCPT ); Tue, 10 Aug 2021 10:22:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:52806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242717AbhHJOS2 (ORCPT ); Tue, 10 Aug 2021 10:18:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DF9C561076; Tue, 10 Aug 2021 14:16:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628605005; bh=ePZz+sF9yOD/Cf5qf8TlpbkemcR8a+vrRB0qNX7C4KA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K94jQAktXOMpkRZ6tXW2W6Jbcm4IxfcgDZuYJ4iDYkWqfuTShBmZzIUPLeAvQfdZ4 VcXHPelxs6rb2VUz/974Dks+L/WrNgFrQaGb9Nnz8Ok+aLljOLg3KimfK1qqoMvLq+ S7+yw6FpQlyErfsguq1jALsL3vUTGRAKh5X0KTU5Yh4AiicpuUspj3D0Lz7/PhEb3Q BWeAT0QjDCgHRH414Gpfm8kgQG9hf+lny1JLba1WA7dWYNqxHY0YgnF992tucDW5hf dHvRdk5nU9JXgGYlmnEieB9esOZp5ZQBN9KqhtoML2G0WgLzuJ90C12MouznvHMFYB LEbdp7TN90L8Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Ujfalusi , Vinod Koul , Sasha Levin , dmaengine@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 03/10] dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available Date: Tue, 10 Aug 2021 10:16:34 -0400 Message-Id: <20210810141641.3118360-3-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210810141641.3118360-1-sashal@kernel.org> References: <20210810141641.3118360-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org From: Peter Ujfalusi [ Upstream commit eda97cb095f2958bbad55684a6ca3e7d7af0176a ] If the router_xlate can not find the controller in the available DMA devices then it should return with -EPORBE_DEFER in a same way as the of_dma_request_slave_channel() does. The issue can be reproduced if the event router is registered before the DMA controller itself and a driver would request for a channel before the controller is registered. In of_dma_request_slave_channel(): 1. of_dma_find_controller() would find the dma_router 2. ofdma->of_dma_xlate() would fail and returned NULL 3. -ENODEV is returned as error code with this patch we would return in this case the correct -EPROBE_DEFER and the client can try to request the channel later. Signed-off-by: Peter Ujfalusi Link: https://lore.kernel.org/r/20210717190021.21897-1-peter.ujfalusi@gmail.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/of-dma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index 8344a60c2131..a9d3ab94749b 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -68,8 +68,12 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec, return NULL; ofdma_target = of_dma_find_controller(&dma_spec_target); - if (!ofdma_target) - return NULL; + if (!ofdma_target) { + ofdma->dma_router->route_free(ofdma->dma_router->dev, + route_data); + chan = ERR_PTR(-EPROBE_DEFER); + goto err; + } chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target); if (IS_ERR_OR_NULL(chan)) { @@ -80,6 +84,7 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec, chan->route_data = route_data; } +err: /* * Need to put the node back since the ofdma->of_dma_route_allocate * has taken it for generating the new, translated dma_spec -- 2.30.2