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Date: Wed, 14 Feb 2024 09:14:42 +0100
From: Horatiu Vultur <horatiu.vultur@microchip.com>
To: Florian Fainelli <f.fainelli@gmail.com>
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Subject: Re: [PATCH net-next] net: sparx5: Add spinlock for frame
 transmission from CPU
Message-ID: <20240214081442.w533wvcvqpvq5352@DEN-DL-M31836.microchip.com>
References: <20240213121705.4070598-1-horatiu.vultur@microchip.com>
 <5476743f-3648-4038-97f8-a9df22c0f507@gmail.com>
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In-Reply-To: <5476743f-3648-4038-97f8-a9df22c0f507@gmail.com>

The 02/13/2024 09:26, Florian Fainelli wrote:
> 
> On 2/13/24 04:17, Horatiu Vultur wrote:
> > Both registers used when doing manual injection or fdma injection are
> > shared between all the net devices of the switch. It was noticed that
> > when having two process which each of them trying to inject frames on
> > different ethernet ports, that the HW started to behave strange, by
> > sending out more frames then expected. When doing fdma injection it is
> > required to set the frame in the DCB and then make sure that the next
> > pointer of the last DCB is invalid. But because there is no locks for
> > this, then easily this pointer between the DCB can be broken and then it
> > would create a loop of DCBs. And that means that the HW will
> > continuously transmit these frames in a loop. Until the SW will break
> > this loop.
> > Therefore to fix this issue, add a spin lock for when accessing the
> > registers for manual or fdma injection.
> > 
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> 
> Any reason you targeted 'net-next' rather than 'net', as this appears to
> be clearly a bug fix here?

Yes, it is a bug but it is not something that happens all the
time and I thought this fits more into the lines of 'This could be a
problem ...' therefore I had targeted 'net-next'.
But if you consider that I should target 'net' instead of 'net-next' I
can do that.

> --
> Florian
> 

-- 
/Horatiu