On Mon, Jun 15, 2020 at 03:56:01PM +0300, Vladimir Oltean wrote: > On Mon, 15 Jun 2020 at 15:35, Mark Brown <broonie@xxxxxxxxxx> wrote: > > > > > > > Indeed. The upshot of all this is that the interrupt needs to be freed > > not disabled before the clocks are disabled, or some other mechanism > > needs to be used to ensure that the interrupt handler won't attempt to > > access the hardware when it shouldn't. As Vladimir says there are > > serious issues using devm for interrupt handlers (or anything else that > > might cause code to be run) due to problems like this. > > And the down-shot is that whatever is done in dspi_remove (free_irq) > also needs to be done in dspi_suspend, but with extra care in > dspi_resume not only to request the irq again, but also to flush the > module's FIFOs and clear interrupts, because there might have been > nasty stuff uncaught during sleep: > > regmap_update_bits(dspi->regmap, SPI_MCR, > SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF, > SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF); > regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR); > > So it's pretty messy. It is a slightly different bug which so this patch should have a follow up. Best regards, Krzysztof
