V4L/DVB (13581): DiBUSB: fix I2c access when there is a read-access w/o write sequence
This patch fixes the behaviour of the dibusb-i2c-access which was previously changed to avoid accidental EEprom writes:
Now it allow i2c-reads without prepended i2c-writes, but it is still not doing anything in case the EEprom is addressed.
Thanks to Mario Bachmann for testing.
Tested-by: Mario Bachmann <grafgrimm77@gmx.de>
Cc: Mario Bachmann <grafgrimm77@gmx.de>
Signed-off-by: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/dvb-usb/dibusb-common.c b/drivers/media/dvb/dvb-usb/dibusb-common.c
index b395e85..9143b56 100644
--- a/drivers/media/dvb/dvb-usb/dibusb-common.c
+++ b/drivers/media/dvb/dvb-usb/dibusb-common.c
@@ -142,8 +142,13 @@
} else if ((msg[i].flags & I2C_M_RD) == 0) {
if (dibusb_i2c_msg(d, msg[i].addr, msg[i].buf,msg[i].len,NULL,0) < 0)
break;
- } else
- break;
+ } else if (msg[i].addr != 0x50) {
+ /* 0x50 is the address of the eeprom - we need to protect it
+ * from dibusb's bad i2c implementation: reads without
+ * writing the offset before are forbidden */
+ if (dibusb_i2c_msg(d, msg[i].addr, NULL, 0, msg[i].buf, msg[i].len) < 0)
+ break;
+ }
}
mutex_unlock(&d->i2c_mutex);