Re: [PATCH 2/3] net: stmmac: Always use the number of configured TX queues

[Thierry Reding]

On Tue, Mar 28, 2017 at 04:10:43PM +0200, Niklas Cassel wrote:
> 
> 
> On 03/28/2017 03:57 PM, Thierry Reding wrote:
> > From: Thierry Reding 
> > 
> > Even if hardware supports multiple queues, software can choose to only
> > use a subset of them. Make sure we never try to access uninitialized
> > queues.
> > 
> > Signed-off-by: Thierry Reding 
> > ---
> >  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c 
> > b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > index 106ace3781b3..ec5bba85c529 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > @@ -3423,7 +3423,7 @@ static int stmmac_poll(struct napi_struct *napi, int 
> > budget)
> > struct stmmac_rx_queue *rx_q =
> > container_of(napi, struct stmmac_rx_queue, napi);
> > struct stmmac_priv *priv = rx_q->priv_data;
> > -   u32 tx_count = priv->dma_cap.number_tx_queues;
> > +   u32 tx_count = priv->plat->tx_queues_to_use;
> > u32 chan = rx_q->queue_index;
> > u32 work_done = 0;
> > u32 queue = 0;
> > 
> 
> Thanks Thierry,
> but this look like an equivalent patch to Joao's
> "net: stmmac: fix number of tx queues in stmmac_poll"
> which I already used during bisecting to avoid random
> crashes in stmmac_tx_clean.

Yeah, patch 3/3 is the important one in this batch. I just sent out the
complete set of 3 because it's what I use on top of linux-next to make
stmmac work again on my setup.

> Have you noticed random RX brokenness after boot in
> recent linux-next tags?

Yes, I was seeing about 8 in 10 bad boots and 2 in 10 good ones.

> It feels like it might trigger more often after a
> cold boot, but that could just be my brain seeing
> patterns that aren't really there :)

It'd be good if you could try applying patch 3/3 since that got me back
to 10/10 successful boots. It's somewhat surprising because I had gone
through the code looking for uninitialized data that would explain why
kcalloc() instead of kmalloc_array() would fix things but didn't find
anything.

Still, that patch works for me, so maybe I was just overlooking
something.

Thierry


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Re: [PATCH 2/3] net: stmmac: Always use the number of configured TX queues

[Niklas Cassel]

On 03/28/2017 03:57 PM, Thierry Reding wrote:
> From: Thierry Reding 
> 
> Even if hardware supports multiple queues, software can choose to only
> use a subset of them. Make sure we never try to access uninitialized
> queues.
> 
> Signed-off-by: Thierry Reding 
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c 
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 106ace3781b3..ec5bba85c529 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -3423,7 +3423,7 @@ static int stmmac_poll(struct napi_struct *napi, int 
> budget)
>   struct stmmac_rx_queue *rx_q =
>   container_of(napi, struct stmmac_rx_queue, napi);
>   struct stmmac_priv *priv = rx_q->priv_data;
> - u32 tx_count = priv->dma_cap.number_tx_queues;
> + u32 tx_count = priv->plat->tx_queues_to_use;
>   u32 chan = rx_q->queue_index;
>   u32 work_done = 0;
>   u32 queue = 0;
> 

Thanks Thierry,
but this look like an equivalent patch to Joao's
"net: stmmac: fix number of tx queues in stmmac_poll"
which I already used during bisecting to avoid random
crashes in stmmac_tx_clean.

Have you noticed random RX brokenness after boot in
recent linux-next tags?

It feels like it might trigger more often after a
cold boot, but that could just be my brain seeing
patterns that aren't really there :)

[PATCH 2/3] net: stmmac: Always use the number of configured TX queues

[Thierry Reding]

From: Thierry Reding 

Even if hardware supports multiple queues, software can choose to only
use a subset of them. Make sure we never try to access uninitialized
queues.

Signed-off-by: Thierry Reding 
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c 
b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 106ace3781b3..ec5bba85c529 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3423,7 +3423,7 @@ static int stmmac_poll(struct napi_struct *napi, int 
budget)
struct stmmac_rx_queue *rx_q =
container_of(napi, struct stmmac_rx_queue, napi);
struct stmmac_priv *priv = rx_q->priv_data;
-   u32 tx_count = priv->dma_cap.number_tx_queues;
+   u32 tx_count = priv->plat->tx_queues_to_use;
u32 chan = rx_q->queue_index;
u32 work_done = 0;
u32 queue = 0;
-- 
2.12.0