Re: [PATCH] spi: dw: Fix broken dw_spi_mem_ops()

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 2/9/22 07:52, Niklas Cassel wrote:
> From: Niklas Cassel <niklas.cassel@wdc.com>
> 
> The driver is currently using sizeof(op->cmd.opcode) in the op_len
> calculation. Commit d15de623013c ("spi: spi-mem: allow specifying a
> command's extension") changed op->cmd.opcode from one byte to two.
> 
> Instead, a new struct member op->cmd.nbytes is supposed to be used.
> For regular commands op->cmd.nbytes will be one.
> 
> Commit d15de623013c ("spi: spi-mem: allow specifying a command's
> extension") did update some drivers that overload the generic mem_ops()
> implementation, but forgot to update dw_spi_mem_ops().
> 
> Calculating op_len incorrectly causes dw_spi_mem_ops() to misbehave, since
> op_len is used to determine how many bytes that should be read/written.
> 
> On the canaan k210 board, this causes the probe of the SPI flash to fail.
> 
> Fix the op_len calculation in dw_spi_mem_ops(). Doing so results in
> working SPI flash on the canaan k210 board.
> 
> Fixes: d15de623013c ("spi: spi-mem: allow specifying a command's extension")
> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
> ---
>  drivers/spi/designware_spi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/designware_spi.c b/drivers/spi/designware_spi.c
> index 742121140d..fc22f540fe 100644
> --- a/drivers/spi/designware_spi.c
> +++ b/drivers/spi/designware_spi.c
> @@ -572,7 +572,7 @@ static int dw_spi_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
>  	int pos, i, ret = 0;
>  	struct udevice *bus = slave->dev->parent;
>  	struct dw_spi_priv *priv = dev_get_priv(bus);
> -	u8 op_len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
> +	u8 op_len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
>  	u8 op_buf[op_len];
>  	u32 cr0;
>  

Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>


-- 
Damien Le Moal
Western Digital Research