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* [PATCH v2] eeprom: at24: fix reading from 24MAC402/24MAC602
@ 2017-11-27 19:46 Heiner Kallweit
  2017-11-27 19:59 ` Heiner Kallweit
  2017-11-29 14:57 ` Bartosz Golaszewski
  0 siblings, 2 replies; 6+ messages in thread
From: Heiner Kallweit @ 2017-11-27 19:46 UTC (permalink / raw)
  To: Bartosz Golaszewski; +Cc: linux-i2c

Chip datasheet mentions that word addresses other than the actual
start position of the MAC delivers undefined results. So fix this.
Current implementation doesn't work due to this wrong offset.

Fixes: 0b813658c115 "eeprom: at24: add support for at24mac series"
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
v2:
- extended commit message
---
 drivers/misc/eeprom/at24.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index e0b4b36ef..00d602be7 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -425,7 +425,8 @@ static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf,
 	memset(msg, 0, sizeof(msg));
 	msg[0].addr = client->addr;
 	msg[0].buf = addrbuf;
-	addrbuf[0] = 0x90 + offset;
+	/* EUI-48 starts from 0x9a, EUI-64 from 0x98 */
+	addrbuf[0] = 0xa0 - at24->chip.byte_len + offset;
 	msg[0].len = 1;
 	msg[1].addr = client->addr;
 	msg[1].flags = I2C_M_RD;
-- 
2.15.0

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2017-11-29 14:57 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-11-27 19:46 [PATCH v2] eeprom: at24: fix reading from 24MAC402/24MAC602 Heiner Kallweit
2017-11-27 19:59 ` Heiner Kallweit
2017-11-27 20:07   ` Heiner Kallweit
2017-11-27 21:10     ` Bartosz Golaszewski
2017-11-27 21:47       ` Heiner Kallweit
2017-11-29 14:57 ` Bartosz Golaszewski

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