HI Akshay,
On 3 June 2014 06:37, 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
Acked-by: Simon Glass sjg@chromium.org
(see comment below - could update this patch or do a follow-on to improve speed of both tx and rx)
Changes since v1: - Added check for step.
drivers/spi/exynos_spi.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/spi/exynos_spi.c b/drivers/spi/exynos_spi.c index 4d5def2..68d1206 100644 --- a/drivers/spi/exynos_spi.c +++ b/drivers/spi/exynos_spi.c @@ -302,6 +302,11 @@ static int spi_rx_tx(struct exynos_spi_slave *spi_slave, int todo, } } else { if (rxp || stopping) {
if (step == 4) {*(rxp + 3) = temp >> 24;*(rxp + 2) = temp >> 16;*(rxp + 1) = temp >> 8;}
BTW I just had another look at the code - sorry I didn't notice this before, but you know that rxp is word-aligned so you can just do *((uint32_t *)rxp) = temp;
*rxp = temp; rxp += step; }-- 1.7.12.4