Re: [PATCH net-next] net: stmmac: dwxgmac2: configure INTM for per-channel interrupt routing

[Maxime Chevallier]

Hi,

On 7/23/26 15:24, Zxyan Zhu wrote:
> The XGMAC DMA_MODE register has an INTM field (bits 13:12) that
> controls interrupt routing behavior for DMA transfer completion
> events:
> 
>   00 (default): sbd_perch_* are pulse signals, sbd_intr_o is also
>                 asserted for each completion event.
>   01:          sbd_perch_* are level signals, sbd_intr_o is NOT
>                 asserted for packet transfer completion events.
> 
> When multi-MSI is enabled (dma_cfg->multi_msi_en), per-channel TX/RX
> interrupts are expected to arrive on their dedicated lines
> (sbd_perch_tx_intr_o / sbd_perch_rx_intr_o).  In the default INTM=00
> mode, sbd_intr_o also fires for DMA completion events, but the
> multi-MSI handler stmmac_mac_interrupt() only processes MAC-layer
> events (LPI, PMT, timestamps) and does not service DMA channels,
> silently dropping the interrupt.
> 
> Set INTM to mode 1 when multi-MSI is enabled, following the same
> pattern as the GMAC4 DMA_BUS_MODE_INTM configuration in commit
> 6ccf12ae111e ("net: stmmac: use interrupt mode INTM=1 for multi-MSI").
> 
> Signed-off-by: Zxyan Zhu <zxyan0222@xxxxxxxxx>

Same logic as in dwmac4, this looks good to me,

Reviewed-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>

Maxime