Commit 38ffcd10 authored by Patrick Boettcher's avatar Patrick Boettcher Committed by Mauro Carvalho Chehab

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: default avatarMario Bachmann <grafgrimm77@gmx.de>
Cc: Mario Bachmann <grafgrimm77@gmx.de>
Signed-off-by: default avatarPatrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent d995a187
...@@ -142,8 +142,13 @@ static int dibusb_i2c_xfer(struct i2c_adapter *adap,struct i2c_msg msg[],int num ...@@ -142,8 +142,13 @@ static int dibusb_i2c_xfer(struct i2c_adapter *adap,struct i2c_msg msg[],int num
} else if ((msg[i].flags & I2C_M_RD) == 0) { } 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) if (dibusb_i2c_msg(d, msg[i].addr, msg[i].buf,msg[i].len,NULL,0) < 0)
break; break;
} else } else if (msg[i].addr != 0x50) {
break; /* 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); mutex_unlock(&d->i2c_mutex);
......
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