Re: [PATCH 2/2] Revert "[media] saa7164: Improvements for I2C handling"

[Antti Palosaari <crope@iki.fi>]

On 06/06/2015 10:44 AM, Olli Salonen wrote:
> This reverts commit ad90b6b0f10566d4a5546e27fe455ce3b5e6b6c7.
>
> This patch breaks I2C communication towards Si2168. After reverting and
> applying the other patch in this series the I2C communication is
> correct.
>
> Signed-off-by: Olli Salonen <olli.salonen@iki.fi>

Reviewed-by: Antti Palosaari <crope@iki.fi>

Antti

> ---
>   drivers/media/pci/saa7164/saa7164-api.c | 11 +----------
>   1 file changed, 1 insertion(+), 10 deletions(-)
>
> diff --git a/drivers/media/pci/saa7164/saa7164-api.c b/drivers/media/pci/saa7164/saa7164-api.c
> index e807703..e7e586c 100644
> --- a/drivers/media/pci/saa7164/saa7164-api.c
> +++ b/drivers/media/pci/saa7164/saa7164-api.c
> @@ -1385,8 +1385,7 @@ int saa7164_api_i2c_read(struct saa7164_i2c *bus, u8 addr, u32 reglen, u8 *reg,
>   	 *       08... register address
>   	 */
>   	memset(buf, 0, sizeof(buf));
> -	if (reg)
> -		memcpy((buf + 2 * sizeof(u32) + 0), reg, reglen);
> +	memcpy((buf + 2 * sizeof(u32) + 0), reg, reglen);
>   	*((u32 *)(buf + 0 * sizeof(u32))) = reglen;
>   	*((u32 *)(buf + 1 * sizeof(u32))) = datalen;
>
> @@ -1475,14 +1474,6 @@ int saa7164_api_i2c_write(struct saa7164_i2c *bus, u8 addr, u32 datalen,
>   	 *       04-07 dest bytes to write
>   	 *       08... register address
>   	 */
> -	if (datalen == 1) {
> -		/* Workaround for issues with i2c components
> -		 * that issue writes with no data. IE: SI2168/2157
> -		 * Increase reglen by 1, strobe out an additional byte,
> -		 * ignored by SI2168/2157.
> -		 */
> -		datalen++;
> -	}
>   	*((u32 *)(buf + 0 * sizeof(u32))) = reglen;
>   	*((u32 *)(buf + 1 * sizeof(u32))) = datalen - reglen;
>   	memcpy((buf + 2 * sizeof(u32)), data, datalen);
>

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