Às 4:42 PM de 3/21/2017, Thierry Reding escreveu:
> On Tue, Mar 21, 2017 at 03:23:00PM +0000, Joao Pinto wrote:
>> Às 3:12 PM de 3/21/2017, Thierry Reding escreveu:
>>> From: Thierry Reding <tred...@nvidia.com>
>>>
>>> Prior to the recent multi-queue changes the driver would configure the
>>> queues to use the AVB mode, but the mode then got switched to DCB. The
>>> hardware still works fine in DCB mode, but my testing capabilities are
>>> limited, so it's safer to revert to the prior setting anyway.
>>>
>>> Signed-off-by: Thierry Reding <tred...@nvidia.com>
>>> ---
>>> include/linux/stmmac.h | 4 ++--
>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
>>> index be47b859e954..8349a5c1537b 100644
>>> --- a/include/linux/stmmac.h
>>> +++ b/include/linux/stmmac.h
>>> @@ -56,8 +56,8 @@
>>> #define MTL_RX_ALGORITHM_WSP 0x5
>>>
>>> /* RX/TX Queue Mode */
>>> -#define MTL_QUEUE_DCB 0x0
>>> -#define MTL_QUEUE_AVB 0x1
>>> +#define MTL_QUEUE_AVB 0x0
>>> +#define MTL_QUEUE_DCB 0x1
>>>
>>> /* The MDC clock could be set higher than the IEEE 802.3
>>> * specified frequency limit 0f 2.5 MHz, by programming a clock divider
>>>
>>
>> Thierry, I don't understand this patch. It will have 0 impact.
>>
>> In stmmac_platform configuration, 0 impact:
>>
>> if (of_property_read_bool(q_node, "snps,dcb-algorithm"))
>> plat->rx_queues_cfg[queue].mode_to_use = MTL_QUEUE_DCB;
>> else if (of_property_read_bool(q_node, "snps,avb-algorithm"))
>> plat->rx_queues_cfg[queue].mode_to_use = MTL_QUEUE_AVB;
>> else
>> ** plat->rx_queues_cfg[queue].mode_to_use = MTL_QUEUE_DCB;
>>
>> In dwmac4_core, 0 impact:
>>
>> value &= GMAC_RX_QUEUE_CLEAR(queue);
>> if (mode == MTL_QUEUE_AVB)
>> value |= GMAC_RX_AV_QUEUE_ENABLE(queue);
>> else if (mode == MTL_QUEUE_DCB)
>> value |= GMAC_RX_DCB_QUEUE_ENABLE(queue);
>>
>> I think you should set the default mode in (**).
>
> That was my initial attempt, but then I realized that for old DTBs,
> stmmac_mtl_setup() will already exit prematurely because of the missing
> snps,mtl-{rx,tx}-config properties. It's pretty much for the same reason
> as the separate assignment of the default {rx,tx}_queues_to_use. In this
> case it's somewhat more obfuscated, though. Changing AVB to be mode 0
> means that plat->rx_queues_cfg[].mode_to_use will contain AVB as default
> because plat is devm_kzalloc()'ed.
>
> Effectively this change makes all queues use AVB by default unless they
> are configured using the new device tree bindings.
Yes I keep forgeting that :), but you are assuming that
plat->rx_queues_cfg[queue].mode_to_use is 0 by default, which might not be the
case, but I agree with you that this is the simpler approach. Let's see what
others have to say.
>
> Thierry
>
