2020-07-22 08:40:29

by Jon Lin

Subject: [PATCH v2 3/3] spi: rockchip: Fix error in SPI slave pio read

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

Signed-off-by: Jon Lin <[email protected]>
Reviewed-by: Heiko Stuebner <[email protected]>
---
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..75a8a9428ff8 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

2020-07-22 12:12:02

by Emil Renner Berthing

Subject: Re: [PATCH v2 3/3] spi: rockchip: Fix error in SPI slave pio read

On Wed, 22 Jul 2020 at 10:38, Jon Lin <[email protected]> wrote:
>
> The RXFLR is possible larger than rx_left in Rockchip SPI, fix it.
>
> Signed-off-by: Jon Lin <[email protected]>
> Reviewed-by: Heiko Stuebner <[email protected]>

In addition to my review and test you should probably also add
Fixes: 01b59ce5dac8 ("spi: rockchip: use irq rather than polling")
..so this will be picked up in the stable trees

/Emil

> ---
> 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..75a8a9428ff8 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
>
>
>
>
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