Re: [PATCH v2 2/4] spi: spi-fsl-dspi: Fix delete the processing of undefined bitmask for rxdata

From: Esben Haabendal
Date: Sun Sep 30 2018 - 06:29:24 EST


Chuanhua Han <chuanhua.han@xxxxxxx> writes:

> This patch fixes the problem of rxdata being equal to 0 during the XSPI
> mode transfer of the dspi controller.
> In XSPI mode, If it is not deleted, the value of rxdata will be equal
> to 0, and the data received will not be received correctly, causing the
> receiving transfer of the spi to fail.
>
> Signed-off-by: Chuanhua Han <chuanhua.han@xxxxxxx>
> ---
> Changes in v2:
> -The original patch is divided into multiple patches(the original
> patch theme is "spi: spi-fsl-dspi: Fix support for XSPI transport
> mode"),one of which is segmented.
>
> drivers/spi/spi-fsl-dspi.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
> index 3082e72e4f6c..4dc1064bf408 100644
> --- a/drivers/spi/spi-fsl-dspi.c
> +++ b/drivers/spi/spi-fsl-dspi.c
> @@ -243,9 +243,6 @@ static void dspi_push_rx(struct fsl_dspi *dspi, u32 rxdata)
> if (!dspi->rx)
> return;
>
> - /* Mask of undefined bits */
> - rxdata &= (1 << dspi->bits_per_word) - 1;

What is the dspi->bits_per_word value when your rxdata is set equal to
0? Could this perhaps also be related to byte ordering problems?

> if (dspi->bytes_per_word == 1)
> *(u8 *)dspi->rx = rxdata;
> else if (dspi->bytes_per_word == 2)

/Esben