From ad90b6b0f10566d4a5546e27fe455ce3b5e6b6c7 Mon Sep 17 00:00:00 2001 From: Steven Toth Date: Mon, 23 Mar 2015 15:42:53 -0300 Subject: [PATCH] [media] saa7164: Improvements for I2C handling Workaround oddball I2C issues caused by using newer SILABS devices. Signed-off-by: Steven Toth Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/pci/saa7164/saa7164-api.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/media/pci/saa7164/saa7164-api.c b/drivers/media/pci/saa7164/saa7164-api.c index 97bbd0a..d9e21e7 100644 --- a/drivers/media/pci/saa7164/saa7164-api.c +++ b/drivers/media/pci/saa7164/saa7164-api.c @@ -1385,7 +1385,8 @@ int saa7164_api_i2c_read(struct saa7164_i2c *bus, u8 addr, u32 reglen, u8 *reg, * 08... register address */ memset(buf, 0, sizeof(buf)); - memcpy((buf + 2 * sizeof(u32) + 0), reg, reglen); + if (reg) + memcpy((buf + 2 * sizeof(u32) + 0), reg, reglen); *((u32 *)(buf + 0 * sizeof(u32))) = reglen; *((u32 *)(buf + 1 * sizeof(u32))) = datalen; @@ -1473,6 +1474,14 @@ 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); -- 2.7.4