From 4c7cad4bbf718e73a49e236e2b79489f1ee83810 Mon Sep 17 00:00:00 2001 From: Antti Palosaari Date: Thu, 7 Jan 2016 06:35:21 -0200 Subject: [PATCH] [media] rtl28xxu: retry failed i2c messages Sometimes i2c transfer fails. That happens especially when large amount of data is written sequentially eg. firmware download. Problem arises with both integrated rtl2832 demod and external mn88472 demod, which is clear indicator it is busy i2c bus issue. Use i2c core retry logic in order fix the issue by repeating failed message. Another solution which also works is to add ~100us delay between i2c messages - but repeating sounds more elegant and does not cause any extra delay for success cases. Signed-off-by: Antti Palosaari Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/dvb-usb-v2/rtl28xxu.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c index eb5787a3191e..c4c6e92e8643 100644 --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c @@ -259,6 +259,10 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = -EOPNOTSUPP; } + /* Retry failed I2C messages */ + if (ret == -EPIPE) + ret = -EAGAIN; + err_mutex_unlock: mutex_unlock(&d->i2c_mutex); @@ -619,6 +623,10 @@ static int rtl28xxu_identify_state(struct dvb_usb_device *d, const char **name) } dev_dbg(&d->intf->dev, "chip_id=%u\n", dev->chip_id); + /* Retry failed I2C messages */ + d->i2c_adap.retries = 1; + d->i2c_adap.timeout = msecs_to_jiffies(10); + return WARM; err: dev_dbg(&d->intf->dev, "failed=%d\n", ret); -- 2.30.2