Re: [PATCH 1/3] i2c: rcar: sanity check for minimal DMA length

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Mar 05, 2019 at 06:54:32PM +0100, Wolfram Sang wrote:
> Use a macro for the hardcoded value and apply a build check. If it is
> not met, the driver logic will not work anymore.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>

Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>

> ---
>  drivers/i2c/busses/i2c-rcar.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
> index 3ce74edcd70c..925858915569 100644
> --- a/drivers/i2c/busses/i2c-rcar.c
> +++ b/drivers/i2c/busses/i2c-rcar.c
> @@ -85,6 +85,7 @@
>  /* ICFBSCR */
>  #define TCYC17	0x0f		/* 17*Tcyc delay 1st bit between SDA and SCL */
>  
> +#define RCAR_MIN_DMA_LEN	8
>  
>  #define RCAR_BUS_PHASE_START	(MDBS | MIE | ESG)
>  #define RCAR_BUS_PHASE_DATA	(MDBS | MIE)
> @@ -412,8 +413,8 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
>  	int len;
>  
>  	/* Do various checks to see if DMA is feasible at all */
> -	if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE) ||
> -	    (read && priv->flags & ID_P_NO_RXDMA))
> +	if (IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN ||
> +	    !(msg->flags & I2C_M_DMA_SAFE) || (read && priv->flags & ID_P_NO_RXDMA))
>  		return;
>  
>  	if (read) {
> @@ -921,6 +922,9 @@ static int rcar_i2c_probe(struct platform_device *pdev)
>  	struct i2c_timings i2c_t;
>  	int irq, ret;
>  
> +	/* Otherwise logic will break because some bytes must always use PIO */
> +	BUILD_BUG_ON_MSG(RCAR_MIN_DMA_LEN < 3, "Invalid min DMA length");
> +
>  	priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
>  	if (!priv)
>  		return -ENOMEM;
> -- 
> 2.11.0
> 



[Index of Archives]     [Linux GPIO]     [Linux SPI]     [Linux Hardward Monitoring]     [LM Sensors]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux