On Sun, 14 Jun 2020 at 13:57, Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
>
> If interrupt comes late, during probe error path or device remove (could
> be triggered with CONFIG_DEBUG_SHIRQ), the interrupt handler
> dspi_interrupt() will access registers with the clock being disabled. This
> leads to external abort on non-linefetch on Toradex Colibri VF50 module
> (with Vybrid VF5xx):
>
> $ echo 4002d000.spi > /sys/devices/platform/soc/40000000.bus/4002d000.spi/driver/unbind
>
> Unhandled fault: external abort on non-linefetch (0x1008) at 0x8887f02c
> Internal error: : 1008 [#1] ARM
> CPU: 0 PID: 136 Comm: sh Not tainted 5.7.0-next-20200610-00009-g5c913fa0f9c5-dirty #74
> Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
> (regmap_mmio_read32le) from [<8061885c>] (regmap_mmio_read+0x48/0x68)
> (regmap_mmio_read) from [<8060e3b8>] (_regmap_bus_reg_read+0x24/0x28)
> (_regmap_bus_reg_read) from [<80611c50>] (_regmap_read+0x70/0x1c0)
> (_regmap_read) from [<80611dec>] (regmap_read+0x4c/0x6c)
> (regmap_read) from [<80678ca0>] (dspi_interrupt+0x3c/0xa8)
> (dspi_interrupt) from [<8017acec>] (free_irq+0x26c/0x3cc)
> (free_irq) from [<8017dcec>] (devm_irq_release+0x1c/0x20)
> (devm_irq_release) from [<805f98ec>] (release_nodes+0x1e4/0x298)
> (release_nodes) from [<805f9ac8>] (devres_release_all+0x40/0x60)
> (devres_release_all) from [<805f5134>] (device_release_driver_internal+0x108/0x1ac)
> (device_release_driver_internal) from [<805f521c>] (device_driver_detach+0x20/0x24)
>
> The resource-managed framework should not be used for interrupt handling,
> because the resource will be released too late - after disabling clocks.
> The interrupt handler is not prepared for such case.
>
> Fixes: 349ad66c0ab0 ("spi:Add Freescale DSPI driver for Vybrid VF610 platform")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
>
> ---
I don't buy this argument that "the resource-managed framework should
not be used for interrupt handling". What is it there for, then?
Could you just call disable_irq before clk_disable_unprepare instead
of this massive rework?
>
> This is an follow up of my other patch for I2C IMX driver [1]. Let's fix the
> issues consistently.
>
> [1] https://lore.kernel.org/lkml/1592130544-19759-2-git-send-email-krzk@xxxxxxxxxx/T/#u
> ---
> drivers/spi/spi-fsl-dspi.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
> index 58190c94561f..57e7a626ba00 100644
> --- a/drivers/spi/spi-fsl-dspi.c
> +++ b/drivers/spi/spi-fsl-dspi.c
> @@ -1385,8 +1385,8 @@ static int dspi_probe(struct platform_device *pdev)
> goto poll_mode;
> }
>
> - ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt,
> - IRQF_SHARED, pdev->name, dspi);
> + ret = request_threaded_irq(dspi->irq, dspi_interrupt, NULL,
> + IRQF_SHARED, pdev->name, dspi);
> if (ret < 0) {
> dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
> goto out_clk_put;
> @@ -1400,7 +1400,7 @@ static int dspi_probe(struct platform_device *pdev)
> ret = dspi_request_dma(dspi, res->start);
> if (ret < 0) {
> dev_err(&pdev->dev, "can't get dma channels\n");
> - goto out_clk_put;
> + goto out_free_irq;
> }
> }
>
> @@ -1415,11 +1415,14 @@ static int dspi_probe(struct platform_device *pdev)
> ret = spi_register_controller(ctlr);
> if (ret != 0) {
> dev_err(&pdev->dev, "Problem registering DSPI ctlr\n");
> - goto out_clk_put;
> + goto out_free_irq;
> }
>
> return ret;
>
> +out_free_irq:
> + if (dspi->irq > 0)
> + free_irq(dspi->irq, dspi);
> out_clk_put:
> clk_disable_unprepare(dspi->clk);
> out_ctlr_put:
> @@ -1435,6 +1438,8 @@ static int dspi_remove(struct platform_device *pdev)
>
> /* Disconnect from the SPI framework */
> dspi_release_dma(dspi);
> + if (dspi->irq > 0)
> + free_irq(dspi->irq, dspi);
> clk_disable_unprepare(dspi->clk);
> spi_unregister_controller(dspi->ctlr);
>
> --
> 2.7.4
>
Thanks,
-Vladimir
