[PATCH net-next 2/9] net: stmmac: dwmac4: fix RX FIFO fill statistics

[Maxime Chevallier]

On 06/01/2026 21:31, Russell King (Oracle) wrote:
> In dwmac4_debug(), the wrong shift is used with the RXFSTS mask:
> 
>  #define MTL_DEBUG_RXFSTS_MASK          GENMASK(5, 4)
>  #define MTL_DEBUG_RXFSTS_SHIFT         4
>  #define MTL_DEBUG_RRCSTS_SHIFT         1
> 
>                        u32 rxfsts = (value & MTL_DEBUG_RXFSTS_MASK)
>                                     >> MTL_DEBUG_RRCSTS_SHIFT;
> 
> where rxfsts is tested against small integers 1 .. 3. This results in
> the tests always failing, causing the "mtl_rx_fifo__fill_level_empty"
> statistic counter to always be incremented no matter what the fill
> level actually is.
> 
> Fix this by using FIELD_GET() and remove the unnecessary
> MTL_DEBUG_RXFSTS_SHIFT definition as FIELD_GET() will shift according
> to the least siginificant set bit in the supplied field mask.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>

Reviewed-by: Maxime Chevallier <maxime.chevallier at bootlin.com>

Maxime