On 14-02-24, 13:29, Nuno Sa wrote:
> In axi_dmac_probe(), there's a mix in using device managed APIs and
> explicitly cleaning things in the driver .remove() hook. Move to use
> device managed APIs and thus drop the .remove() hook.
>
> While doing this move request_irq() before of_dma_controller_register()
> so the previous cleanup order in the .remove() hook is preserved.
It is good that we are doing this, but moving irq to devm doesnt help a
lot, there exists a race
I would suggest you use the axi_dmac_free_dma_controller() to all free
up irq explicitly, that will ensure things no chance of irq firing and
scheduling tasklet when we are removing
>
> Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
> ---
> drivers/dma/dma-axi-dmac.c | 80 ++++++++++++++++++++--------------------------
> 1 file changed, 35 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
> index 4e339c04fc1e..24c911dc3161 100644
> --- a/drivers/dma/dma-axi-dmac.c
> +++ b/drivers/dma/dma-axi-dmac.c
> @@ -1002,6 +1002,16 @@ static int axi_dmac_detect_caps(struct axi_dmac *dmac, unsigned int version)
> return 0;
> }
>
> +static void axi_dmac_tasklet_kill(void *task)
> +{
> + tasklet_kill(task);
> +}
> +
> +static void axi_dmac_free_dma_controller(void *of_node)
> +{
> + of_dma_controller_free(of_node);
> +}
> +
> static int axi_dmac_probe(struct platform_device *pdev)
> {
> struct dma_device *dma_dev;
> @@ -1025,14 +1035,10 @@ static int axi_dmac_probe(struct platform_device *pdev)
> if (IS_ERR(dmac->base))
> return PTR_ERR(dmac->base);
>
> - dmac->clk = devm_clk_get(&pdev->dev, NULL);
> + dmac->clk = devm_clk_get_enabled(&pdev->dev, NULL);
> if (IS_ERR(dmac->clk))
> return PTR_ERR(dmac->clk);
>
> - ret = clk_prepare_enable(dmac->clk);
> - if (ret < 0)
> - return ret;
> -
> version = axi_dmac_read(dmac, ADI_AXI_REG_VERSION);
>
> if (version >= ADI_AXI_PCORE_VER(4, 3, 'a'))
> @@ -1041,7 +1047,7 @@ static int axi_dmac_probe(struct platform_device *pdev)
> ret = axi_dmac_parse_dt(&pdev->dev, dmac);
>
> if (ret < 0)
> - goto err_clk_disable;
> + return ret;
>
> INIT_LIST_HEAD(&dmac->chan.active_descs);
>
> @@ -1072,7 +1078,7 @@ static int axi_dmac_probe(struct platform_device *pdev)
>
> ret = axi_dmac_detect_caps(dmac, version);
> if (ret)
> - goto err_clk_disable;
> + return ret;
>
> dma_dev->copy_align = (dmac->chan.address_align_mask + 1);
>
> @@ -1088,57 +1094,42 @@ static int axi_dmac_probe(struct platform_device *pdev)
> !AXI_DMAC_DST_COHERENT_GET(ret)) {
> dev_err(dmac->dma_dev.dev,
> "Coherent DMA not supported in hardware");
> - ret = -EINVAL;
> - goto err_clk_disable;
> + return -EINVAL;
> }
> }
>
> - ret = dma_async_device_register(dma_dev);
> + ret = dmaenginem_async_device_register(dma_dev);
> + if (ret)
> + return ret;
> +
> + /*
> + * Put the action in here so it get's done before unregistering the DMA
> + * device.
> + */
> + ret = devm_add_action_or_reset(&pdev->dev, axi_dmac_tasklet_kill,
> + &dmac->chan.vchan.task);
> + if (ret)
> + return ret;
> +
> + ret = devm_request_irq(&pdev->dev, dmac->irq, axi_dmac_interrupt_handler,
> + IRQF_SHARED, dev_name(&pdev->dev), dmac);
> if (ret)
> - goto err_clk_disable;
> + return ret;
>
> ret = of_dma_controller_register(pdev->dev.of_node,
> of_dma_xlate_by_chan_id, dma_dev);
> if (ret)
> - goto err_unregister_device;
> + return ret;
>
> - ret = request_irq(dmac->irq, axi_dmac_interrupt_handler, IRQF_SHARED,
> - dev_name(&pdev->dev), dmac);
> + ret = devm_add_action_or_reset(&pdev->dev, axi_dmac_free_dma_controller,
> + pdev->dev.of_node);
> if (ret)
> - goto err_unregister_of;
> -
> - platform_set_drvdata(pdev, dmac);
> + return ret;
>
> regmap = devm_regmap_init_mmio(&pdev->dev, dmac->base,
> &axi_dmac_regmap_config);
> - if (IS_ERR(regmap)) {
> - ret = PTR_ERR(regmap);
> - goto err_free_irq;
> - }
> -
> - return 0;
> -
> -err_free_irq:
> - free_irq(dmac->irq, dmac);
> -err_unregister_of:
> - of_dma_controller_free(pdev->dev.of_node);
> -err_unregister_device:
> - dma_async_device_unregister(&dmac->dma_dev);
> -err_clk_disable:
> - clk_disable_unprepare(dmac->clk);
> -
> - return ret;
> -}
> -
> -static void axi_dmac_remove(struct platform_device *pdev)
> -{
> - struct axi_dmac *dmac = platform_get_drvdata(pdev);
>
> - of_dma_controller_free(pdev->dev.of_node);
> - free_irq(dmac->irq, dmac);
> - tasklet_kill(&dmac->chan.vchan.task);
> - dma_async_device_unregister(&dmac->dma_dev);
> - clk_disable_unprepare(dmac->clk);
> + return PTR_ERR_OR_ZERO(regmap);
> }
>
> static const struct of_device_id axi_dmac_of_match_table[] = {
> @@ -1153,7 +1144,6 @@ static struct platform_driver axi_dmac_driver = {
> .of_match_table = axi_dmac_of_match_table,
> },
> .probe = axi_dmac_probe,
> - .remove_new = axi_dmac_remove,
> };
> module_platform_driver(axi_dmac_driver);
>
>
> ---
> base-commit: de7d9cb3b064fdfb2e0e7706d14ffee20b762ad2
> change-id: 20240214-axi-dmac-devm-probe-d718ef36fb58
> --
>
> Thanks!
> - Nuno Sá
--
~Vinod
