Hi Akshay,
On 30 May 2014 07:45, Akshay Saraswat akshay.s@samsung.com wrote:
SPI recieve and transfer code in exynos_spi driver has a logical bug. We read data in a variable which can hold an integer. Then we assign this integer 32 bit value to another variable which has data type uchar. Latter represents a unit of our recieve buffer. Everytime when we write a value to our recieve buffer we step ahead by 4 units when actually we wrote to one unit. This results in the loss of 3 bytes out of every 4 bytes recieved. This patch intends to fix this bug.
Signed-off-by: Akshay Saraswat akshay.s@samsung.com
drivers/spi/exynos_spi.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/spi/exynos_spi.c b/drivers/spi/exynos_spi.c index 4d5def2..b9fd618 100644 --- a/drivers/spi/exynos_spi.c +++ b/drivers/spi/exynos_spi.c @@ -302,6 +302,9 @@ static int spi_rx_tx(struct exynos_spi_slave *spi_slave, int todo, } } else { if (rxp || stopping) {
*(rxp + 3) = (temp >> 24);*(rxp + 2) = (temp >> 16);*(rxp + 1) = (temp >> 8); *rxp = temp; rxp += step;
Here step is either 1 (bytes) or 4 (words). So I think you are making an assumption here. If you look up a bit you can see what it does for txp (two cases for step being 1 or 4) and I think you should do the same here.
Regards, Simon