[PATCH v2 1/1] spi-mxs: Fix chipselect glitch

[Ralf Schlatterbeck]

On Fri, Feb 02, 2024 at 12:53:30PM +0100, Ralf Schlatterbeck wrote:
> There was a change in the mxs-dma engine that uses a new custom flag.
> The change was not applied to the mxs spi driver.
> This results in chipselect being deasserted too early.
> This fixes the chipselect problem by using the new flag in the mxs-spi
> driver.
> 
> Fixes: ceeeb99cd821 ("dmaengine: mxs: rename custom flag")
> Signed-off-by: Ralf Schlatterbeck <rsc at runtux.com>
> ---
> For oscilloscope screenshots and a verbose explanation see my blog post
> at https://blog.runtux.com/posts/2024/02/01/
> History:
> Omit the line break change from patch requested by Marc Kleine-Budde
> <mkl at pengutronix.de>
> 
>  drivers/spi/spi-mxs.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c
> index 1bf080339b5a..88cbe4f00cc3 100644
> --- a/drivers/spi/spi-mxs.c
> +++ b/drivers/spi/spi-mxs.c
> @@ -39,6 +39,7 @@
>  #include <linux/spi/spi.h>
>  #include <linux/spi/mxs-spi.h>
>  #include <trace/events/spi.h>
> +#include <linux/dma/mxs-dma.h>
>  
>  #define DRIVER_NAME		"mxs-spi"
>  
> @@ -252,7 +253,7 @@ static int mxs_spi_txrx_dma(struct mxs_spi *spi,
>  		desc = dmaengine_prep_slave_sg(ssp->dmach,
>  				&dma_xfer[sg_count].sg, 1,
>  				(flags & TXRX_WRITE) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
> -				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
> +				DMA_PREP_INTERRUPT | MXS_DMA_CTRL_WAIT4END);
>  
>  		if (!desc) {
>  			dev_err(ssp->dev,
> -- 
> 2.20.1
> 
> -- 
> Dr. Ralf Schlatterbeck                  Tel:   +43/2243/26465-16
> Open Source Consulting                  www:   www.runtux.com
> Reichergasse 131, A-3411 Weidling       email: office at runtux.com

Any news on this, will it be picked up for the next merge window?

Thanks + kind regards
Ralf Schlatterbeck
-- 
Dr. Ralf Schlatterbeck                  Tel:   +43/2243/26465-16
Open Source Consulting                  www:   www.runtux.com
Reichergasse 131, A-3411 Weidling       email: office at runtux.com