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

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Message-ID: <20200515122700.GY185537@smile.fi.intel.com>
Date:   Fri, 15 May 2020 15:27:00 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Serge Semin <Sergey.Semin@...kalelectronics.ru>
Cc:     Mark Brown <broonie@...nel.org>,
        Serge Semin <fancer.lancer@...il.com>,
        Georgy Vlasov <Georgy.Vlasov@...kalelectronics.ru>,
        Ramil Zaripov <Ramil.Zaripov@...kalelectronics.ru>,
        Alexey Malahov <Alexey.Malahov@...kalelectronics.ru>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Paul Burton <paulburton@...nel.org>,
        Ralf Baechle <ralf@...ux-mips.org>,
        Arnd Bergmann <arnd@...db.de>,
        Allison Randal <allison@...utok.net>,
        Gareth Williams <gareth.williams.jx@...esas.com>,
        Rob Herring <robh+dt@...nel.org>, linux-mips@...r.kernel.org,
        devicetree@...r.kernel.org,
        Jarkko Nikula <jarkko.nikula@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@...el.com>,
        linux-spi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 05/19] spi: dw: Enable interrupts in accordance with
 DMA xfer mode

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@...kalelectronics.ru>
> Signed-off-by: Georgy Vlasov <Georgy.Vlasov@...kalelectronics.ru>
> Signed-off-by: Serge Semin <Sergey.Semin@...kalelectronics.ru>
> Cc: Ramil Zaripov <Ramil.Zaripov@...kalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@...kalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@...ha.franken.de>
> Cc: Paul Burton <paulburton@...nel.org>
> Cc: Ralf Baechle <ralf@...ux-mips.org>
> Cc: Arnd Bergmann <arnd@...db.de>
> Cc: Allison Randal <allison@...utok.net>
> Cc: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> Cc: Gareth Williams <gareth.williams.jx@...esas.com>
> Cc: Rob Herring <robh+dt@...nel.org>
> Cc: linux-mips@...r.kernel.org
> Cc: devicetree@...r.kernel.org

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)

-- 
With Best Regards,
Andy Shevchenko