950-0332-bcm2835-mmc-Fix-DMA-channel-leak.patch

From 7458efc95816cc9d716d94a4894172c2a9d9fba7 Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas@wunner.de>
Date: Wed, 16 Jan 2019 12:22:32 +0100
Subject: [PATCH] bcm2835-mmc: Fix DMA channel leak

The BCM2835 MMC host driver requests a DMA channel on probe but neglects
to release the channel in the probe error path and on driver unbind.

I'm seeing this happen on every boot of the Compute Module 3: On first
driver probe, DMA channel 2 is allocated and then leaked with a "could
not get clk, deferring probe" message. On second driver probe, channel 4
is allocated.

Fix it.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Frank Pavlic <f.pavlic@kunbus.de>
---
 drivers/mmc/host/bcm2835-mmc.c | 5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/mmc/host/bcm2835-mmc.c
+++ b/drivers/mmc/host/bcm2835-mmc.c
@@ -1503,6 +1503,8 @@ static int bcm2835_mmc_probe(struct plat
 
 	return 0;
 err:
+	if (host->dma_chan_rxtx)
+		dma_release_channel(host->dma_chan_rxtx);
 	mmc_free_host(mmc);
 
 	return ret;
@@ -1548,6 +1550,9 @@ static int bcm2835_mmc_remove(struct pla
 
 	tasklet_kill(&host->finish_tasklet);
 
+	if (host->dma_chan_rxtx)
+		dma_release_channel(host->dma_chan_rxtx);
+
 	mmc_free_host(host->mmc);
 	platform_set_drvdata(pdev, NULL);