[PATCH 1/3] i2c: at91: release DMA channels on remove and probe error
From: Shengzhuo Wei <hidden>
Date: 2026-08-27 15:43:20
Also in:
imx, linux-arm-msm, linux-i2c, lkml, stable
Subsystem:
i2c subsystem, i2c subsystem host drivers, microchip i2c driver, the rest · Maintainers:
Andi Shyti, Codrin Ciubotariu, Linus Torvalds
at91_twi_configure_dma() requests exclusive tx/rx DMA channels, but
nothing ever releases them on driver detach, and the probe error path
after the channels are acquired (i2c_add_numbered_adapter() failure)
returns without releasing them either, because the remove callback is
not invoked after a failed probe.
Move the release into a helper, call it from the existing
configure-failure path, the adapter-registration failure path, and
at91_twi_remove().
Fixes: 60937b2cdbf9 ("i2c: at91: add dma support")
Cc: stable@vger.kernel.org
Signed-off-by: Shengzhuo Wei <redacted>
Assisted-by: GLM:5.3
---
drivers/i2c/busses/i2c-at91-core.c | 3 +++
drivers/i2c/busses/i2c-at91-master.c | 12 +++++++++++-
drivers/i2c/busses/i2c-at91.h | 1 +
3 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c
index b64adef778d4..8ca4556d9664 100644
--- a/drivers/i2c/busses/i2c-at91-core.c
+++ b/drivers/i2c/busses/i2c-at91-core.c@@ -255,6 +255,7 @@ static int at91_twi_probe(struct platform_device *pdev) if (rc) { pm_runtime_disable(dev->dev); pm_runtime_set_suspended(dev->dev); + at91_twi_dma_release(dev); return rc; }
@@ -270,6 +271,8 @@ static void at91_twi_remove(struct platform_device *pdev) i2c_del_adapter(&dev->adapter); + at91_twi_dma_release(dev); + pm_runtime_disable(dev->dev); pm_runtime_set_suspended(dev->dev); }
diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
index 894cedbca99f..68238cc8aee0 100644
--- a/drivers/i2c/busses/i2c-at91-master.c
+++ b/drivers/i2c/busses/i2c-at91-master.c@@ -817,11 +817,21 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) error: if (ret != -EPROBE_DEFER) dev_info(dev->dev, "can't get DMA channel, continue without DMA support\n"); + at91_twi_dma_release(dev); + return ret; +} + +void at91_twi_dma_release(struct at91_twi_dev *dev) +{ + struct at91_twi_dma *dma = &dev->dma; + if (dma->chan_rx) dma_release_channel(dma->chan_rx); if (dma->chan_tx) dma_release_channel(dma->chan_tx); - return ret; + dma->chan_rx = NULL; + dma->chan_tx = NULL; + dev->use_dma = false; } static int at91_init_twi_recovery_gpio(struct platform_device *pdev,
diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h
index 942e9c3973bb..d68fcbbc3e0f 100644
--- a/drivers/i2c/busses/i2c-at91.h
+++ b/drivers/i2c/busses/i2c-at91.h@@ -172,6 +172,7 @@ void at91_twi_irq_restore(struct at91_twi_dev *dev); void at91_init_twi_bus(struct at91_twi_dev *dev); void at91_init_twi_bus_master(struct at91_twi_dev *dev); +void at91_twi_dma_release(struct at91_twi_dev *dev); int at91_twi_probe_master(struct platform_device *pdev, u32 phy_addr, struct at91_twi_dev *dev);
--
2.47.3