Re: [PATCH] igb: restore EEPROM 16kB access limit

[Stefan Assmann <sassmann@kpanic.de>]

On 08.04.2011 18:40, Wyborny, Carolyn wrote:
> 
> 
>> -----Original Message-----
>> From: Stefan Assmann [mailto:sassmann@kpanic.de]
>> Sent: Friday, April 08, 2011 6:35 AM
>> To: netdev@vger.kernel.org
>> Cc: e1000-devel@lists.sourceforge.net; Kirsher, Jeffrey T; Pieper,
>> Jeffrey E; Wyborny, Carolyn; Ronciak, John
>> Subject: [PATCH] igb: restore EEPROM 16kB access limit
>>
>> The check limiting the EEPROM access up to 16kB was removed by
>> commit 4322e561a93ec7ee034b603a6c610e7be90d4e8a. Without this check
>> the kernel will try to checksum the EEPROM up to 2MB (observed with
>> a 8086:10c9 NIC) and fail.
>>
>> igb 0000:03:00.0: 0 vfs allocated
>> igb 0000:03:00.0: The NVM Checksum Is Not Valid
>> ACPI: PCI interrupt for device 0000:03:00.0 disabled
>> igb: probe of 0000:03:00.0 failed with error -5
>>
>> Reason for that being an overflow in u16 e1000_nvm_info->nvm
>> while doing "nvm->word_size = 1 << size;" with size == 21.
>> Putting the check back in place.
>>
>> Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
>> ---
>> drivers/net/igb/e1000_82575.c |    4 ++++
>> 1 files changed, 4 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/net/igb/e1000_82575.c
>> b/drivers/net/igb/e1000_82575.c
>> index 6b256c2..5cfa37f 100644
>> --- a/drivers/net/igb/e1000_82575.c
>> +++ b/drivers/net/igb/e1000_82575.c
>> @@ -244,6 +244,10 @@ static s32 igb_get_invariants_82575(struct e1000_hw
>> *hw)
>> 	 */
>> 	size += NVM_WORD_SIZE_BASE_SHIFT;
>>
>> +	/* EEPROM access above 16k is unsupported */
>> +	if (size > 14)
>> +		size = 14;
>> +
>> 	nvm->word_size = 1 << size;
>> 	if (nvm->word_size == (1 << 15))
>> 		nvm->page_size = 128;
>> --
>> 1.7.4
> NACK
> 
> This doesn't apply against current upstream RC kernel.  There was more changed in that commit than just the removal of this.  There is a missing section of code that is needed, but not this.  This starts at line 251 in e1000_82575.c

Carolyn,

the patch applies against latest net-next-2.6
(782d640afd15af7a1faf01cfe566ca4ac511319d).

How do you explain the behaviour observed in the patch description?

> 
> --snip--
>         /* NVM Function Pointers */
>         nvm->ops.acquire = igb_acquire_nvm_82575;
>         if (nvm->word_size < (1 << 15))
>                 nvm->ops.read = igb_read_nvm_eerd;
>         else
>                 nvm->ops.read = igb_read_nvm_spi;
> --snip--

Ok, so I assume some new NICs allow access beyond the 16k boundary.
In that case we should identify which NICs and treat them separately,
keeping the behaviour identical for the others.

  Stefan