Re: [PATCH v1 3/3] spi: rockchip: Fix error in SPI slave pio read

[Heiko Stübner]

Hi Jon,

Am Mittwoch, 22. Juli 2020, 08:52:57 CEST schrieb Jon Lin:
> The RXFLR is possible larger than rx_left in Rockchip SPI, fix it.
> 
> Signed-off-by: Jon Lin 
> ---
>  drivers/spi/spi-rockchip.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
> index a451dacab5cf..1f5e613b67d9 100644
> --- a/drivers/spi/spi-rockchip.c
> +++ b/drivers/spi/spi-rockchip.c
> @@ -291,7 +291,7 @@ static void rockchip_spi_pio_writer(struct rockchip_spi 
> *rs)
>  static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
>  {
>   u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
> - u32 rx_left = rs->rx_left - words;
> + u32 rx_left = rs->rx_left > words ? rs->rx_left - words : 0;

I guess for future readability of the code braces might be nice, like

u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;

But I stumbled onto (and fixed similarly) that issue yesterday as well, so

Reviewed-by: Heiko Stuebner 


Heiko

[PATCH v1 3/3] spi: rockchip: Fix error in SPI slave pio read

[Jon Lin]

The RXFLR is possible larger than rx_left in Rockchip SPI, fix it.

Signed-off-by: Jon Lin 
---
 drivers/spi/spi-rockchip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index a451dacab5cf..1f5e613b67d9 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -291,7 +291,7 @@ static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
 {
u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
-   u32 rx_left = rs->rx_left - words;
+   u32 rx_left = rs->rx_left > words ? rs->rx_left - words : 0;
 
/* the hardware doesn't allow us to change fifo threshold
 * level while spi is enabled, so instead make sure to leave
-- 
2.17.1