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V4L/DVB (9585): Skip reading eeprom in newer Empia devices 

Empia switched to a 16-bit addressable eeprom in newer devices.  While we
could certainly write a routine to read the eeprom, there is nothing of use
in there that cannot be accessed through registers, and there is the risk that
we could corrupt the eeprom (since a 16-bit read call is interpreted as a
write call by 8-bit eeproms).  So just be safe and bail out of the function.

Thanks for Ray Lu from Empia for providing the em2874 datasheet.

Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Devin Heitmueller 2008-11-12 02:05:10 -03:00 committed by Mauro Carvalho Chehab
parent 6a1acc3bc5
commit a527c9f827
1 changed files with 11 additions and 0 deletions
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11
drivers/media/video/em28xx/em28xx-i2c.c
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@ -332,6 +332,17 @@ static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned char *eedata, int len)
struct em28xx_eeprom *em_eeprom = (void *)eedata; struct em28xx_eeprom *em_eeprom = (void *)eedata;
int i, err, size = len, block; int i, err, size = len, block;
if (dev->chip_id == CHIP_ID_EM2874) {
/* Empia switched to a 16-bit addressable eeprom in newer
devices. While we could certainly write a routine to read
the eeprom, there is nothing of use in there that cannot be
accessed through registers, and there is the risk that we
could corrupt the eeprom (since a 16-bit read call is
interpreted as a write call by 8-bit eeproms).
*/
return 0;
}
dev->i2c_client.addr = 0xa0 >> 1; dev->i2c_client.addr = 0xa0 >> 1;
/* Check if board has eeprom */ /* Check if board has eeprom */