Re: [PATCH v2] stmmac: CSR clock configuration fix

[Phil Reid <preid@electromag.com.au>]

On 22/12/2016 23:47, Joao Pinto wrote:
>
> Hello Phil,
>
> Às 3:42 PM de 12/22/2016, Phil Reid escreveu:
>> G'day Joao,
>>
>> On 22/12/2016 20:38, Joao Pinto wrote:
>>> When testing stmmac with my QoS reference design I checked a problem in the
>>> CSR clock configuration that was impossibilitating the phy discovery, since
>>> every read operation returned 0x0000ffff. This patch fixes the issue.
>>>
>>> Signed-off-by: Joao Pinto <jpinto@synopsys.com>
>>> ---
>>> changes v1->v2 (David Miller)
>>> - DWMAC100 and DWMAC1000 csr clocks masks should also be fixed for the patch
>>> to make sense
>>>
>>>  drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c | 2 +-
>>>  drivers/net/ethernet/stmicro/stmmac/dwmac100_core.c  | 2 +-
>>>  drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c    | 8 ++++----
>>>  3 files changed, 6 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
>>> b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
>>> index b21d03f..94223c8 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
>>> @@ -539,7 +539,7 @@ struct mac_device_info *dwmac1000_setup(void __iomem
>>> *ioaddr, int mcbins,
>>>      mac->mii.reg_shift = 6;
>>>      mac->mii.reg_mask = 0x000007C0;
>>>      mac->mii.clk_csr_shift = 2;
>>> -    mac->mii.clk_csr_mask = 0xF;
>>> +    mac->mii.clk_csr_mask = GENMASK(4, 2);
>>
>> Should this not be GENMASK(5,2)
>
> According to Universal MAC databook (valid for MAC100 and MAC1000), we have:
>
> Bits: 4:2
> 000 60-100 MHz clk_csr_i/42
> 001 100-150 MHz clk_csr_i/62
> 010 20-35 MHz clk_csr_i/16
> 011 35-60 MHz clk_csr_i/26
> 100 150-250 MHz clk_csr_i/102
> 101 250-300 MHz clk_csr_i/124
> 110, 111 Reserved
>
> So only bits 2, 3 and 4 should be masked.
>
> Thanks.
>
But this is a change in behaviour from what was there isn't.
Previous mask was 4 bits. now it's 3.

And for example the altera socfgpa implementation in the cyclone V has valid values
for values 0x8-0xf, using bit 5:2.





-- 
Regards
Phil Reid