From patchwork Sat Jul 17 19:00:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?P=C3=A9ter_Ujfalusi?= X-Patchwork-Id: 12383817 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 DDEBFC636CA for ; Sat, 17 Jul 2021 18:58:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B189A61073 for ; Sat, 17 Jul 2021 18:58:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234971AbhGQTAx (ORCPT ); Sat, 17 Jul 2021 15:00:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234308AbhGQTAw (ORCPT ); Sat, 17 Jul 2021 15:00:52 -0400 Received: from mail-lj1-x233.google.com (mail-lj1-x233.google.com [IPv6:2a00:1450:4864:20::233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07939C061762; Sat, 17 Jul 2021 11:57:54 -0700 (PDT) Received: by mail-lj1-x233.google.com with SMTP id e20so18904460ljn.8; Sat, 17 Jul 2021 11:57:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=G7SgY/YkC3Ua+jZHJBroQqKVwZij5nIyA73xwLEzGtY=; b=azpXn0L6T/BYABVMVJEUJotU+wwq+cL167r2uYNQs+8UylC9M3oqcSAxr2mo67Aiqj tHKWmFZwluW9IhlIIJL5jh5LRr4YBkzEcnieZ+VTe4kSlt3Huuf6xJ16bHB62qJC945w zamxsXltj95M9is/WUEgPH8TP4VQ5pqV8/xNdS92qjtuxjhWUWvKzT41Bw6r0D1M0+of jFqspNyjhZp1rqj8rucQuNi3d+p03jm8dvFevosce9nVAzeFLSxIlxeViXN/KrYz08RY 36QHs6rm5KX+G6XacgBrvXAbhWizYtEIeGMLAAgFn+rWsQnZ7adJ8+JIRU3VIn3XOFkS FP0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=G7SgY/YkC3Ua+jZHJBroQqKVwZij5nIyA73xwLEzGtY=; b=NJKHcBMwwx7xclaS3DP26u5EW3WG4raPRJpkD6Ol5+9IK7fsBcl5hY3zNAAmGKGmny 7r6LZe+61syHiL27sMslIhscYmK341dg4NfyR2bTl/7+66yP3VLPZpeYU7TJ7/f91hfX VhuqzG+swvCYxxjZ60F67+nbf6aHZ8wZenWPl6Alznyvc4oLF6SetriuiYkvDc4sbA6L iSc7mqfQ1vAsfDPxltAxTZ0IxCzlyXfxzyNt7IeTaDpfJVaxXq8+8pwBnguv/2jTFLSB ICo2qzSPuwXZEU1MFvVA5uheQLidCjwotTFyks3I+qKf+mXuSjQTF8XpmfecjDuJCJ8N uzYw== X-Gm-Message-State: AOAM531L9TaiX4Yl7f6D3H93vd2Hr6lerjaqxUHNLiIPblTXbcmgXZ9J A9TBDAKzQ0BybC8GxuIUZKU= X-Google-Smtp-Source: ABdhPJytwHKWFIxg2qCR2S1vk1mrAMA0owY0ottAGsurh4pfMKr5eVxPEAWChikE6waQ2Fpnvz1WzQ== X-Received: by 2002:a05:651c:882:: with SMTP id d2mr5538178ljq.370.1626548273245; Sat, 17 Jul 2021 11:57:53 -0700 (PDT) Received: from localhost.localdomain (91-155-111-71.elisa-laajakaista.fi. [91.155.111.71]) by smtp.gmail.com with ESMTPSA id a26sm1406319ljq.120.2021.07.17.11.57.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 17 Jul 2021 11:57:52 -0700 (PDT) From: Peter Ujfalusi To: vkoul@kernel.org Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, tony@atomide.com, nm@ti.com Subject: [PATCH] dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available Date: Sat, 17 Jul 2021 22:00:21 +0300 Message-Id: <20210717190021.21897-1-peter.ujfalusi@gmail.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org 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 --- Hi, I have noticed the descibed failure sequence on Beagle-x15 board (McASP fails to probe). It must have been broken for some time, I have not booted the board for about a year or so... Regards, Peter 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 ec00b20ae8e4..ac61ecda2926 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -67,8 +67,12 @@ 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)) { @@ -89,6 +93,7 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec, } } +err: /* * Need to put the node back since the ofdma->of_dma_route_allocate * has taken it for generating the new, translated dma_spec