On 23/09/2024 22:37, Mikhail Arkhipov wrote:
> If of_dma_controller_register() fails within the edma_probe() function,
> the driver does not check the return value or log the failure. This
> oversight can cause other drivers that rely on this DMA controller to fail
> during their probe phase. Specifically, when other drivers call
> of_dma_request_slave_channel(), they may receive an error code
> -EPROBE_DEFER, causing their initialization to be delayed or fail without
> clear logging of the root cause.
>
> Add a check for the return value of of_dma_controller_register() in the
> edma_probe() function. If the function returns an error, log an appropriate
> error message and handle the failure by cleaning up resources and returning
> the error code. This ensures that the failure is properly reported, which
> aids in debugging and maintains system stability.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
Acked-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
>
> Fixes: dc9b60552f6a ("ARM/dmaengine: edma: Move of_dma_controller_register to the dmaengine driver")
> Signed-off-by: Mikhail Arkhipov <m.arhipov@xxxxxxx>
> ---
> drivers/dma/ti/edma.c | 17 +++++++++++++----
> 1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/ti/edma.c b/drivers/dma/ti/edma.c
> index 5f8d2e93ff3f..9fcbd97d346f 100644
> --- a/drivers/dma/ti/edma.c
> +++ b/drivers/dma/ti/edma.c
> @@ -2529,18 +2529,27 @@ static int edma_probe(struct platform_device *pdev)
> if (ret) {
> dev_err(dev, "memcpy ddev registration failed (%d)\n",
> ret);
> - dma_async_device_unregister(&ecc->dma_slave);
> - goto err_reg1;
> + goto err_unregister_dma_slave;
> }
> }
>
> - if (node)
> - of_dma_controller_register(node, of_edma_xlate, ecc);
> + if (node) {
> + ret = of_dma_controller_register(node, of_edma_xlate, ecc);
> + if (ret) {
> + dev_err(dev, "Failed to register DMA controller (%d)\n", ret);
> + goto err_unregister_dma_memcpy;
> + }
> + }
>
> dev_info(dev, "TI EDMA DMA engine driver\n");
>
> return 0;
>
> +err_unregister_dma_memcpy:
> + if (ecc->dma_memcpy)
> + dma_async_device_unregister(ecc->dma_memcpy);
> +err_unregister_dma_slave:
> + dma_async_device_unregister(&ecc->dma_slave);
> err_reg1:
> edma_free_slot(ecc, ecc->dummy_slot);
> err_disable_pm:
--
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