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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>,
	Vinod Koul <vkoul@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.4 18/31] dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available
Date: Tue, 24 Aug 2021 13:07:30 -0400	[thread overview]
Message-ID: <20210824170743.710957-19-sashal@kernel.org> (raw)
In-Reply-To: <20210824170743.710957-1-sashal@kernel.org>

From: Peter Ujfalusi <peter.ujfalusi@gmail.com>

[ 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 <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20210717190021.21897-1-peter.ujfalusi@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 86c591481dfe..4a5dbf30605a 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


  parent reply	other threads:[~2021-08-24 17:39 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-24 17:07 [PATCH 4.4 00/31] 4.4.282-rc1 review Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 01/31] ASoC: intel: atom: Fix reference to PCM buffer address Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 02/31] i2c: dev: zero out array used for i2c reads from userspace Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 03/31] net: Fix memory leak in ieee802154_raw_deliver Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 04/31] xen/events: Fix race in set_evtchn_to_irq Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 05/31] x86/tools: Fix objdump version check again Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 06/31] PCI/MSI: Enable and mask MSI-X early Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 07/31] PCI/MSI: Do not set invalid bits in MSI mask Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 08/31] PCI/MSI: Correct misleading comments Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 09/31] PCI/MSI: Use msi_mask_irq() in pci_msi_shutdown() Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 10/31] PCI/MSI: Protect msi_desc::masked for multi-MSI Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 11/31] PCI/MSI: Mask all unused MSI-X entries Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 12/31] PCI/MSI: Enforce that MSI-X table entry is masked for update Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 13/31] PCI/MSI: Enforce MSI[X] entry updates to be visible Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 14/31] vmlinux.lds.h: Handle clang's module.{c,d}tor sections Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 15/31] KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653) Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 16/31] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe() Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 17/31] ARM: dts: am43x-epos-evm: Reduce i2c0 bus speed for tps65218 Sasha Levin
2021-08-24 17:07 ` Sasha Levin [this message]
2021-08-24 17:07 ` [PATCH 4.4 19/31] scsi: megaraid_mm: Fix end of loop tests for list_for_each_entry() Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 20/31] scsi: core: Avoid printing an error if target_alloc() returns -ENXIO Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 21/31] Bluetooth: hidp: use correct wait queue when removing ctrl_wait Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 22/31] dccp: add do-while-0 stubs for dccp_pr_debug macros Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 23/31] net: 6pack: fix slab-out-of-bounds in decode_data Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 24/31] net: qlcnic: add missed unlock in qlcnic_83xx_flash_read32 Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 25/31] mmc: dw_mmc: Wait for data transfer after response errors Sasha Levin
2021-08-26 11:59   ` Nobuhiro Iwamatsu
2021-08-26 12:31     ` Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 26/31] mmc: dw_mmc: call the dw_mci_prep_stop_abort() by default Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 27/31] mmc: dw_mmc: Fix hang on data CRC error Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 28/31] ALSA: hda - fix the 'Capture Switch' value change notifications Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 29/31] ipack: tpci200: fix many double free issues in tpci200_pci_probe Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 30/31] ASoC: intel: atom: Fix breakage for PCM buffer address setup Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 31/31] Linux 4.4.282-rc1 Sasha Levin
2021-08-25  7:33 ` [PATCH 4.4 00/31] 4.4.282-rc1 review Pavel Machek
2021-08-25 20:27 ` Guenter Roeck
2021-08-25 21:18 ` Daniel Díaz
2021-08-25 22:38 ` Shuah Khan

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