Re: Applied "spi: imx: dynamic burst length adjust for PIO mode" to the spi tree

[Jiada Wang]

Hello Sascha

On 06/30/2017 05:14 AM, Sascha Hauer wrote:
> Hi Mark,
>
> On Fri, Jun 30, 2017 at 01:00:22PM +0100, Mark Brown wrote:
> > The patch
> >
> >     spi: imx: dynamic burst length adjust for PIO mode
> >
> > has been applied to the spi tree at
> >
> >     git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git
> Argh, I wasn't fast enough. I just ran spi-loopback-test.ko with this
> patch and it doesn't work properly.
>
> > +	if (spi_imx->count == spi_imx->remainder) {
> > +		ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
> > +		ctrl&= ~MX51_ECSPI_CTRL_BL_MASK;
> > +		if (spi_imx->count>  MX51_ECSPI_CTRL_MAX_BURST) {
> > +			spi_imx->remainder = spi_imx->count %
> > +					     MX51_ECSPI_CTRL_MAX_BURST;
> > +			val = MX51_ECSPI_CTRL_MAX_BURST;
> This is wrong. MX51_ECSPI_CTRL_MAX_BURST contains the burst length in
> bytes, but the register 'val' is written to takes the burst length in
> bits - 1, so this should be:
>
> 			val = MX51_ECSPI_CTRL_MAX_BURST * 8 - 1;
>
> instead.
Thanks for pointing this out,
I will submit a fix patch.


Thanks,
Jiada
> Sascha