[U-Boot] [PATCH 3/3] arm: at91: ether: Prepare for mach-types.h changes

Igor Grinberg
2011-05-02T07:29:45Z

On 05/01/11 22:38, Reinhard Meyer wrote:

> Dear Igor Grinberg,
>
>> at91 ethernet module used machine_is_cbs337() macro for board specific
>> Linux compatibility issue.
>> Use compile time defines instead.
>>
>> Signed-off-by: Igor Grinberg<grinberg@compulab.co.il>
>> ---
>> arch/arm/cpu/arm920t/at91rm9200/ether.c | 18 +++++++++---------
>> 1 files changed, 9 insertions(+), 9 deletions(-)
>>
>> diff --git a/arch/arm/cpu/arm920t/at91rm9200/ether.c b/arch/arm/cpu/arm920t/at91rm9200/ether.c
>> index e1cdeba..4aeb883 100644
>> --- a/arch/arm/cpu/arm920t/at91rm9200/ether.c
>> +++ b/arch/arm/cpu/arm920t/at91rm9200/ether.c
>> @@ -201,15 +201,15 @@ int eth_init (bd_t * bd)
>> * that MicroMonitor behavior so we avoid needing to make such OS code
>> * care about which bootloader was used.
>> */
>> - if (machine_is_csb337()) {
>> - p_mac->EMAC_SA2H = (enetaddr[0]<< 8) | (enetaddr[1]);
>> - p_mac->EMAC_SA2L = (enetaddr[2]<< 24) | (enetaddr[3]<< 16)
>> - | (enetaddr[4]<< 8) | (enetaddr[5]);
>> - } else {
>> - p_mac->EMAC_SA2L = (enetaddr[3]<< 24) | (enetaddr[2]<< 16)
>> - | (enetaddr[1]<< 8) | (enetaddr[0]);
>> - p_mac->EMAC_SA2H = (enetaddr[5]<< 8) | (enetaddr[4]);
>> - }
>> +#ifdef CONFIG_MACH_CSB337
>> + p_mac->EMAC_SA2H = (enetaddr[0]<< 8) | (enetaddr[1]);
>> + p_mac->EMAC_SA2L = (enetaddr[2]<< 24) | (enetaddr[3]<< 16)
>> + | (enetaddr[4]<< 8) | (enetaddr[5]);
>> +#else
>> + p_mac->EMAC_SA2L = (enetaddr[3]<< 24) | (enetaddr[2]<< 16)
>> + | (enetaddr[1]<< 8) | (enetaddr[0]);
>> + p_mac->EMAC_SA2H = (enetaddr[5]<< 8) | (enetaddr[4]);
>> +#endif
>>
>> p_mac->EMAC_RBQP = (long) (&rbfdt[0]);
>> p_mac->EMAC_RSR&= ~(AT91C_EMAC_RSR_OVR | AT91C_EMAC_REC | AT91C_EMAC_BNA);
>
> There is nothing wrong with your patch itself, but it let me to take a closer look at the
> reasoning of why there is a machine dependency. The full code at this section is:
>
> eth_getenv_enetaddr("ethaddr", enetaddr);
>
> /* The CSB337 originally used a version of the MicroMonitor bootloader
> * which saved Ethernet addresses in the "wrong" order. Operating
> * systems (like Linux) know this, and apply a workaround. Replicate
> * that MicroMonitor behavior so we avoid needing to make such OS code
> * care about which bootloader was used.
> */
> if (machine_is_csb337()) {
> p_mac->EMAC_SA2H = (enetaddr[0] << 8) | (enetaddr[1]);
> p_mac->EMAC_SA2L = (enetaddr[2] << 24) | (enetaddr[3] << 16)
> | (enetaddr[4] << 8) | (enetaddr[5]);
> } else {
> p_mac->EMAC_SA2L = (enetaddr[3] << 24) | (enetaddr[2] << 16)
> | (enetaddr[1] << 8) | (enetaddr[0]);
> p_mac->EMAC_SA2H = (enetaddr[5] << 8) | (enetaddr[4]);
> }
>
> So, for the sake of a(nother) broken bootloader and a workaround in Linux we
> store the MAC address in the wrong order? What if U-Boot itself is used to make
> LAN accesses?

Well, I've read the comment before preparing the patch.
Actually, I felt like: "this should be thrown away!".
Also, I haven't found csb337 board in the tree...
I didn't want to decide for you (If I'm not mistaken,
you are the maintainer of Atmel) what to do with it, so I left it.
Do you think we should remove this?
I would love to send another patch to remove this completely.

>
> Apart from that, it feels entirely wrong to do so. Fix the kernel to NOT do a
> workaround instead should be the better approach.

Yep, I totally agree...

>
> Any opinions by Ben or Wolfgang on this?
>

--
Regards,
Igor.