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Date: Tue, 13 Feb 2024 16:22:58 +0000
From: Daniel Machon <daniel.machon@microchip.com>
To: Horatiu Vultur <horatiu.vultur@microchip.com>
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Subject: Re: [PATCH net-next] net: sparx5: Add spinlock for frame
 transmission from CPU
Message-ID: <20240213162258.ajicpzeevveajrz6@DEN-DL-M70577>
References: <20240213121705.4070598-1-horatiu.vultur@microchip.com>
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In-Reply-To: <20240213121705.4070598-1-horatiu.vultur@microchip.com>

> 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.

Reviewed-by: Daniel Machon <daniel.machon@microchip.com>