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

From: Sascha Hauer
Date: Fri Jun 30 2017 - 08:14:43 EST


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.

Sascha

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