[PATCH net] Revert "net: stmmac: Specify hardware capability value when FIFO size isn't specified"

[Russell King (Oracle)]

On Thu, Feb 06, 2025 at 09:08:10AM +0100, Paolo Abeni wrote:
> On 2/5/25 1:57 PM, Russell King (Oracle) wrote:
> > This reverts commit 8865d22656b4, which caused breakage for platforms
> > which are not using xgmac2 or gmac4. Only these two cores have the
> > capability of providing the FIFO sizes from hardware capability fields
> > (which are provided in priv->dma_cap.[tr]x_fifo_size.)
> > 
> > All other cores can not, which results in these two fields containing
> > zero. We also have platforms that do not provide a value in
> > priv->plat->[tr]x_fifo_size, resulting in these also being zero.
> > 
> > This causes the new tests introduced by the reverted commit to fail,
> > and produce e.g.:
> > 
> > 	stmmaceth f0804000.eth: Can't specify Rx FIFO size
> > 
> > An example of such a platform which fails is QEMU's npcm750-evb.
> > This uses dwmac1000 which, as noted above, does not have the capability
> > to provide the FIFO sizes from hardware.
> > 
> > Therefore, revert the commit to maintain compatibility with the way
> > the driver used to work.
> > 
> > Reported-by: Guenter Roeck <linux at roeck-us.net>
> > Link: https://lore.kernel.org/r/4e98f967-f636-46fb-9eca-d383b9495b86@roeck-us.net
> > Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
> 
> Given the fallout caused by the blamed commit, the imminent net PR, and
> the substantial agreement about the patch already shared by many persons
> on the ML, unless someone raises very serious concerns very soon, I'm
> going to apply this patch (a little) earlier than the 24h grace period,
> to fit the mentioned PR.

Thanks. Here's the missing Fixes tag that I missed:

Fixes: 8865d22656b4 ("net: stmmac: Specify hardware capability value when
FIFO size isn't specified")

Not sure if patchwork will pick that up.

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