RE: [PATCH] spi: spi-mem: Adjust op len based on message/transfer size limitations

[Chuanhua Han]

> -----Original Message-----
> From: Chuanhua Han <chuanhua.han@xxxxxxx>
> Sent: 2018年9月21日 15:06
> To: broonie@xxxxxxxxxx
> Cc: linux-spi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; eha@xxxxxxxx;
> boris.brezillon@xxxxxxxxxxx; Chuanhua Han <chuanhua.han@xxxxxxx>;
> stable@xxxxxxxxxxxxxxx
> Subject: [PATCH] spi: spi-mem: Adjust op len based on message/transfer size
> limitations
> 
> We need that to adjust the len of the 2nd transfer (called data in
> spi-mem) if it's too long to fit in a SPI message or SPI transfer.
> 
> Fixes: c36ff266dc82 ("spi: Extend the core to ease integration of SPI memory
> controllers")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Chuanhua Han <chuanhua.han@xxxxxxx>
> Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> ---
>  drivers/spi/spi-mem.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index
> 990770dfa5cf..ec0c24e873cd 100644
> --- a/drivers/spi/spi-mem.c
> +++ b/drivers/spi/spi-mem.c
> @@ -328,10 +328,25 @@ EXPORT_SYMBOL_GPL(spi_mem_exec_op);
>  int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
> {
>  	struct spi_controller *ctlr = mem->spi->controller;
> +	size_t len;
> +
> +	len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
> 
>  	if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
>  		return ctlr->mem_ops->adjust_op_size(mem, op);
> 
> +	if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
> +		if (len > spi_max_transfer_size(mem->spi))
> +			return -EINVAL;
> +
> +		op->data.nbytes = min3((size_t)op->data.nbytes,
> +				       spi_max_transfer_size(mem->spi),
> +				       spi_max_message_size(mem->spi) -
> +				       len);
> +		if (!op->data.nbytes)
> +			return -EINVAL;
> +	}
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
> --
> 2.17.1
I'm really sorry for my error in operation, this has been applied to the latest kernel, please ignore this patch in email!!!