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[23.128.96.18]) by mx.google.com with ESMTP id y9si21846833ilu.22.2021.08.24.10.38.04; Tue, 24 Aug 2021 10:38:15 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=ODfeAs1B; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240135AbhHXRiF (ORCPT + 99 others); Tue, 24 Aug 2021 13:38:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:39252 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242125AbhHXRei (ORCPT ); Tue, 24 Aug 2021 13:34:38 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8AE7B613DA; Tue, 24 Aug 2021 17:06:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824801; bh=Pz46gHkSQln6I3G5DEJdMbJZXyYmt8VVju6zaCEkHR8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ODfeAs1Beixr8T8xuxbMc8sE+blbbgVgR5mEudBs2jWWsyckZMo2W5nzJjk7+UKPt WU7BpUK4kpB5sy0q82Z0pZb4rm3nepedIYO+YCYTMFDpdCdMsyIeygEZwZWPtn17YQ tZIzb3/iEoBxjQUea1pzezTEmgU+MFp6AuSx5MiAfRy4Du+jusVEG7gyNRo2/TmegL m8O8zNnDQVrnJH4KooUSRAo8TdnmNhiht63sfLjRaKsiKtU1AO8DEUq3YBDT8z7x6o DRqCpX1Fuk6tyZ1ueGxtGE96wlscjR5tcJJ5Z6GRkyrNIgPFrfPBaY1vCpzS4VKxVm nArrbQgvFZSqg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Ujfalusi , Vinod Koul , Sasha Levin Subject: [PATCH 4.9 25/43] dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available Date: Tue, 24 Aug 2021 13:05:56 -0400 Message-Id: <20210824170614.710813-26-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824170614.710813-1-sashal@kernel.org> References: <20210824170614.710813-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.281-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.9.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.9.281-rc1 X-KernelTest-Deadline: 2021-08-26T17:06+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 757cf48c1c5e..441f37b41abd 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