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.
Thierry
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