Re: [PATCH] serial: max310x: rework RX interrupt handling

From: Thomas Petazzoni
Date: Wed Sep 30 2020 - 10:50:43 EST


Hello,

On Wed, 30 Sep 2020 17:24:48 +0300
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:

> > On a Microchip SAMA5D3 platform that is receiving 20 bytes every 16ms
> > over one MAX310X UART, this patch has allowed to reduce the CPU
> > consumption of the interrupt handler thread from ~25% to 6-7%.
>
> Was it always like this?

As far as I can see, yes. I guess you were thinking about a Fixes: tag
perhaps? I don't think a Fixes: tag really applies here, as we're not
fixing a performance regression.

> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

> > - /* Configure MODE2 register & Reset FIFOs*/
> > - val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
> > - max310x_port_write(port, MAX310X_MODE2_REG, val);
> > + /* Reset FIFOs*/
>
> Add a space before the asterisk.

Indeed. Let me know if a v2 is needed, or if this small typo can be
fixed when applying.

Thanks,

Thomas
--
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com