Re: [PATCH v2 05/19] spi: dw: Enable interrupts in accordance with DMA xfer mode

From: Serge Semin
Date: Sat May 16 2020 - 10:09:59 EST


On Fri, May 15, 2020 at 03:27:00PM +0300, Andy Shevchenko wrote:
> On Fri, May 15, 2020 at 01:47:44PM +0300, Serge Semin wrote:
> > It's pointless to track the Tx overrun interrupts if Rx-only SPI
> > transfer is issued. Similarly there is no need in handling the Rx
> > overrun/underrun interrupts if Tx-only SPI transfer is executed.
> > So lets unmask the interrupts only if corresponding SPI
> > transactions are implied.
>
> My comments below.
>
> > Co-developed-by: Georgy Vlasov <Georgy.Vlasov@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Georgy Vlasov <Georgy.Vlasov@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Ramil Zaripov <Ramil.Zaripov@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> > Cc: Paul Burton <paulburton@xxxxxxxxxx>
> > Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > Cc: Allison Randal <allison@xxxxxxxxxxx>
> > Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > Cc: Gareth Williams <gareth.williams.jx@xxxxxxxxxxx>
> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> > Cc: linux-mips@xxxxxxxxxxxxxxx
> > Cc: devicetree@xxxxxxxxxxxxxxx
>
> I think you really need to revisit Cc list in all patches (DT people hardly
> interested in this one, though ones where properties are being used might be
> point of interest).
>
> ...
>
> > /* Set the interrupt mask */
> > - spi_umask_intr(dws, SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI);
> > + spi_umask_intr(dws, imr);
>

> Can we rather do like this
>
> /* Set the interrupt mask */
> if (xfer->tx_buf)
> imr |= SPI_INT_TXOI;
> if (xfer->rx_buf)
> imr |= SPI_INT_RXUI | SPI_INT_RXOI;
> spi_umask_intr(dws, imr);
>
> ?
>
> (First block sets DMA, second one IRQ)

I'd rather leave it as is.

-Sergey

>
> --
> With Best Regards,
> Andy Shevchenko
>
>