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| H A D | sfp.c | 28e74a7c Sun Jun 02 09:13:00 CDT 2019 Russell King <rmk+kernel@armlinux.org.uk> net: sfp: read eeprom in maximum 16 byte increments
Some SFP modules do not like reads longer than 16 bytes, so read the
EEPROM in chunks of 16 bytes at a time. This behaviour is not specified
in the SFP MSAs, which specifies:
"The serial interface uses the 2-wire serial CMOS E2PROM protocol
defined for the ATMEL AT24C01A/02/04 family of components."
and
"As long as the SFP+ receives an acknowledge, it shall serially clock
out sequential data words. The sequence is terminated when the host
responds with a NACK and a STOP instead of an acknowledge."
We must avoid breaking a read across a 16-bit quantity in the diagnostic
page, thankfully all 16-bit quantities in that page are naturally
aligned.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
28e74a7c Sun Jun 02 09:13:00 CDT 2019 Russell King <rmk+kernel@armlinux.org.uk> net: sfp: read eeprom in maximum 16 byte increments
Some SFP modules do not like reads longer than 16 bytes, so read the
EEPROM in chunks of 16 bytes at a time. This behaviour is not specified
in the SFP MSAs, which specifies:
"The serial interface uses the 2-wire serial CMOS E2PROM protocol
defined for the ATMEL AT24C01A/02/04 family of components."
and
"As long as the SFP+ receives an acknowledge, it shall serially clock
out sequential data words. The sequence is terminated when the host
responds with a NACK and a STOP instead of an acknowledge."
We must avoid breaking a read across a 16-bit quantity in the diagnostic
page, thankfully all 16-bit quantities in that page are naturally
aligned.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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