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 <[email protected]>
---
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;
+
+ 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) {
+ dev_err(&spi->dev, "Data response error (%02x %02x)\n",
+ rsp[i], rsp[i + 1]);
+ return -1;
+ }
+ return 0;
+}
+
static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
{
struct spi_device *spi = to_spi_device(wilc->dev);
@@ -777,7 +822,10 @@ static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
return result;
}
- return 0;
+ /*
+ * Data response
+ */
+ return spi_data_rsp(wilc, CMD_DMA_EXT_WRITE);
}
/********************************************
--
2.25.1
David Mosberger-Tang <[email protected]> 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 <[email protected]>
> ---
> 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.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
On Thu, 2021-02-25 at 10:27 +0200, Kalle Valo wrote:
> David Mosberger-Tang <[email protected]> writes:
> > + for (i = sizeof(rsp) - 2; i >= 0; --i)
> > + if ((rsp[i] & 0xf0) == 0xc0)
> > + break;
>
> No magic numbers. Please create proper defines for these.]
>
> + if (rsp[i] != 0xc3 || rsp[i + 1] != 0x00) {
>
> Same here.
Good points. I'll change those, thanks.
--david