[PATCH] i2c: at91: release DMA channels when probe defers

[PATCH] i2c: at91: release DMA channels when probe defers

[Hongjian Dai]

at91_twi_probe_master() can return -EPROBE_DEFER from
at91_init_twi_recovery_info() after at91_twi_configure_dma() has already
claimed the tx/rx DMA channels. at91_twi_probe() then returns without
releasing them, and since dma_request_chan() is not devres-managed the
channels leak on every deferred probe attempt.

Release the channels before deferring the probe.

Fixes: f7eeb1af8537 ("i2c: at91: release DMA channels on remove and probe error")
Assisted-by: LLM
Signed-off-by: Hongjian Dai <daihongjian@kylinsec.com.cn>
---
 drivers/i2c/busses/i2c-at91-master.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
index 68238cc8aee0..e0c3de5e8203 100644
--- a/drivers/i2c/busses/i2c-at91-master.c
+++ b/drivers/i2c/busses/i2c-at91-master.c
@@ -921,8 +921,14 @@ int at91_twi_probe_master(struct platform_device *pdev,
 	at91_calc_twi_clock(dev);
 
 	rc = at91_init_twi_recovery_info(pdev, dev);
-	if (rc == -EPROBE_DEFER)
+	if (rc == -EPROBE_DEFER) {
+		/*
+		 * The DMA channels were already set up above, release them
+		 * before deferring the probe so they are not leaked.
+		 */
+		at91_twi_dma_release(dev);
 		return rc;
+	}
 
 	dev->adapter.algo = &at91_twi_algorithm;
 	dev->adapter.quirks = &at91_twi_quirks;
-- 
2.43.0

Re: [PATCH] i2c: at91: release DMA channels when probe defers

[Andi Shyti]

Hi Hongjian,

On Wed, Sep 30, 2026 at 12:43:40AM +0800, Hongjian Dai wrote:
> at91_twi_probe_master() can return -EPROBE_DEFER from
> at91_init_twi_recovery_info() after at91_twi_configure_dma() has already
> claimed the tx/rx DMA channels. at91_twi_probe() then returns without
> releasing them, and since dma_request_chan() is not devres-managed the
> channels leak on every deferred probe attempt.
> 
> Release the channels before deferring the probe.
> 
> Fixes: f7eeb1af8537 ("i2c: at91: release DMA channels on remove and probe error")
> Assisted-by: LLM
> Signed-off-by: Hongjian Dai <daihongjian@kylinsec.com.cn>

pushed to i2c/i2c-fixes.

Thanks,
Andi