On Mon, 15 Jun 2020 at 11:18, Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
>
> On 6/15/20 10:07 AM, Krzysztof Kozlowski 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)
> >
> > Fixes: 349ad66c0ab0 ("spi:Add Freescale DSPI driver for Vybrid VF610 platform")
> > Cc: <stable@xxxxxxxxxxxxxxx>
> > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> >
> > ---
> >
> > 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
> >
> > Changes since v1:
> > 1. Disable the IRQ instead of using non-devm interface.
> > ---
> > drivers/spi/spi-fsl-dspi.c | 9 +++++++--
> > 1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
> > index 58190c94561f..023e05c53b85 100644
> > --- a/drivers/spi/spi-fsl-dspi.c
> > +++ b/drivers/spi/spi-fsl-dspi.c
> > @@ -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 disable_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 disable_irq;
> > }
> >
> > return ret;
> >
> > +disable_irq:
> > + if (dspi->irq > 0)
> > + disable_irq(dspi->irq);
> > 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)
> > + disable_irq(dspi->irq);
>
> What happens, if you re-bind the driver?
> Is the IRQ still working?
> Who is taking care of calling the enable_irq() again?
> What happens, if you really have a shared IRQ line?
> Is the IRQ disabled for all other devices on the same IRQ line?
>
Yup, devm is completely broken for shared IRQs.
> > clk_disable_unprepare(dspi->clk);
> > spi_unregister_controller(dspi->ctlr);
> >
> >
> Marc
>
> --
> Pengutronix e.K. | Marc Kleine-Budde |
> Embedded Linux | https://www.pengutronix.de |
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