When saa7134 module driving a Medion 7134 card is reloaded reads of this card EEPROM (required for automatic detection of tuner model) will be corrupted due to I2C gate in DVB-T demod being left closed. This sometimes also happens on first saa7134 module load after a warm reboot.
Fix this by opening this I2C gate before doing EEPROM read during i2c initialization. Signed-off-by: Maciej S. Szmigiero <m...@maciej.szmigiero.name> --- This is a modified version of patch submitted a few years ago: http://www.spinics.net/lists/linux-media/msg24455.html . That patch was fixing two problems: with TDA9887 detection on cold board and EEPROM read on warm. TDA9887 detection issue have been solved since by commit 4aed283c0f7c2 ("switch tuner FMD1216ME_MK3 to analog"), however EEPROM read issue remained. This submission fixes this a little bit earlier in the code than previous attempt (during i2c initialization instead of later board init) so informational EEPROM read shown in kernel log will also be correct. drivers/media/pci/saa7134/saa7134-i2c.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/drivers/media/pci/saa7134/saa7134-i2c.c b/drivers/media/pci/saa7134/saa7134-i2c.c index 8ef6399d794f..bc957528f69f 100644 --- a/drivers/media/pci/saa7134/saa7134-i2c.c +++ b/drivers/media/pci/saa7134/saa7134-i2c.c @@ -355,12 +355,43 @@ static struct i2c_client saa7134_client_template = { /* ----------------------------------------------------------- */ +/* On Medion 7134 reading EEPROM needs DVB-T demod i2c gate open */ +static void saa7134_i2c_eeprom_md7134_gate(struct saa7134_dev *dev) +{ + u8 subaddr = 0x7, dmdregval; + u8 data[2]; + int ret; + struct i2c_msg i2cgatemsg_r[] = { {.addr = 0x08, .flags = 0, + .buf = &subaddr, .len = 1}, + {.addr = 0x08, + .flags = I2C_M_RD, + .buf = &dmdregval, .len = 1} + }; + struct i2c_msg i2cgatemsg_w[] = { {.addr = 0x08, .flags = 0, + .buf = data, .len = 2} }; + + ret = i2c_transfer(&dev->i2c_adap, i2cgatemsg_r, 2); + if ((ret == 2) && (dmdregval & 0x2)) { + pr_debug("%s: DVB-T demod i2c gate was left closed\n", + dev->name); + + data[0] = subaddr; + data[1] = (dmdregval & ~0x2); + if (i2c_transfer(&dev->i2c_adap, i2cgatemsg_w, 1) != 1) + pr_err("%s: EEPROM i2c gate open failure\n", + dev->name); + } +} + static int saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len) { unsigned char buf; int i,err; + if (dev->board == SAA7134_BOARD_MD7134) + saa7134_i2c_eeprom_md7134_gate(dev); + dev->i2c_client.addr = 0xa0 >> 1; buf = 0; if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
