David Mosberger-Tang <davidm@xxxxxxxxxx> writes:
> After a DMA write to the WILC chip, check for and report any errors.
>
> This is based on code from the wilc driver in the linux-at91
> repository.
>
> Signed-off-by: David Mosberger-Tang <davidm@xxxxxxxxxx>
> ---
> drivers/net/wireless/microchip/wilc1000/spi.c | 50 ++++++++++++++++++-
> 1 file changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c
> index fca34d1999ec..b0e096a03a28 100644
> --- a/drivers/net/wireless/microchip/wilc1000/spi.c
> +++ b/drivers/net/wireless/microchip/wilc1000/spi.c
> @@ -750,6 +750,51 @@ static int wilc_spi_write_reg(struct wilc *wilc, u32 addr, u32 data)
> return 0;
> }
>
> +static int spi_data_rsp(struct wilc *wilc, u8 cmd)
> +{
> + struct spi_device *spi = to_spi_device(wilc->dev);
> + int result, i;
> + u8 rsp[4];
> +
> + /*
> + * The response to data packets is two bytes long. For
> + * efficiency's sake, wilc_spi_write() wisely ignores the
> + * responses for all packets but the final one. The downside
> + * of that optimization is that when the final data packet is
> + * short, we may receive (part of) the response to the
> + * second-to-last packet before the one for the final packet.
> + * To handle this, we always read 4 bytes and then search for
> + * the last byte that contains the "Response Start" code (0xc
> + * in the top 4 bits). We then know that this byte is the
> + * first response byte of the final data packet.
> + */
> + result = wilc_spi_rx(wilc, rsp, sizeof(rsp));
> + if (result) {
> + dev_err(&spi->dev, "Failed bus error...\n");
> + return result;
> + }
> +
> + for (i = sizeof(rsp) - 2; i >= 0; --i)
> + if ((rsp[i] & 0xf0) == 0xc0)
> + break;
No magic numbers. Please create proper defines for these.
> + if (i < 0) {
> + dev_err(&spi->dev,
> + "Data packet response missing (%02x %02x %02x %02x)\n",
> + rsp[0], rsp[1], rsp[2], rsp[3]);
> + return -1;
> + }
> +
> + /* rsp[i] is the last response start byte */
> +
> + if (rsp[i] != 0xc3 || rsp[i + 1] != 0x00) {
Same here.
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