Commit bc6c1eaa authored by Mauro S. M. Rodrigues's avatar Mauro S. M. Rodrigues Committed by Jeff Kirsher
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i40e: Check if transceiver implements DDM before access 



Similar to the ixgbe issue fixed in:
655c9141 ("ixgbe: Check DDM existence in transceiver before access)

i40e has the same issue when reading eeprom from SFP's module that comply
with SFF-8472 but not implement the Digital Diagnostic Monitoring (DDM)
interface described in it. The existence of such area is specified by bit
6 of byte 92, set to 1 if implemented.

Without this patch, due to not checking this bit i40e fails to read SFP
module's eeprom with the follow message:

ethtool -m enP51p1s0f0
Cannot get Module EEPROM data: Input/output error

Because it fails to read the additional 256 bytes in which it was assumed
to exist the DDM data.

Signed-off-by: default avatar"Mauro S. M. Rodrigues" <maurosr@linux.vnet.ibm.com>
Tested-by: default avatarAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent 33b16568

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

+6 −0
Original line number Diff line number Diff line
@@ -5137,6 +5137,12 @@ static int i40e_get_module_info(struct net_device *netdev, 
			/* Module is not SFF-8472 compliant */

			modinfo->type = ETH_MODULE_SFF_8079;

			modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;

		} else if (!(sff8472_swap & I40E_MODULE_SFF_DDM_IMPLEMENTED)) {

			/* Module is SFF-8472 compliant but doesn't implement

			 * Digital Diagnostic Monitoring (DDM).

			 */

			modinfo->type = ETH_MODULE_SFF_8079;

			modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;

		} else {

			modinfo->type = ETH_MODULE_SFF_8472;

			modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;

drivers/net/ethernet/intel/i40e/i40e_type.h

+1 −0
Original line number Diff line number Diff line
@@ -443,6 +443,7 @@ struct i40e_nvm_access { 
#define I40E_MODULE_SFF_8472_COMP	0x5E

#define I40E_MODULE_SFF_8472_SWAP	0x5C

#define I40E_MODULE_SFF_ADDR_MODE	0x04

#define I40E_MODULE_SFF_DDM_IMPLEMENTED 0x40

#define I40E_MODULE_TYPE_QSFP_PLUS	0x0D

#define I40E_MODULE_TYPE_QSFP28		0x11

#define I40E_MODULE_QSFP_MAX_LEN	640