Re: [PATCH v12 19/20] dmaengine: ti: k3-udma-v2: Update glue layer to support PKTDMA V2

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] dmaengine: ti: k3-udma-glue: invalid TX filtering bits written to RX channel CFG
--

commit 80d8898567997b92a02ff1c556dd2a370e753920
Author: Sai Sree Kartheek Adivi <s-adivi@ti.com>

dmaengine: ti: k3-udma-v2: Update glue layer to support PKTDMA V2

This commit updates the glue layer to support PKTDMA V2 for non DMAengine
users. It adds handling for the absence of TISCI, direct IRQs, and TX/RX
channel autopairing.

> diff --git a/drivers/dma/ti/k3-udma-glue.c b/drivers/dma/ti/k3-udma-glue.c
> --- a/drivers/dma/ti/k3-udma-glue.c
> +++ b/drivers/dma/ti/k3-udma-glue.c

[ ... ]

> @@ -728,11 +773,24 @@ static int k3_udma_glue_cfg_rx_chn(struct k3_udma_glue_rx_channel *rx_chn)
>  	req.rx_chan_type = TI_SCI_RM_UDMAP_CHAN_TYPE_PKT_PBRR;
>  	req.rx_atype = rx_chn->common.atype_asel;
>  
> +	if (!tisci_rm->tisci) {
> +		u32 val = 0;
> +
> +		if (!rx_chn->common.epib)
> +			val |= UDMA_CHAN_CFG_FILT_EINFO;
> +		if (!rx_chn->common.psdata_size)
> +			val |= UDMA_CHAN_CFG_FILT_PSWORDS;
> +
> +		xudma_rchanrt_write(rx_chn->udma_rchanx, UDMA_CHAN_RT_CFG_REG, val);

[Severity: Medium]
Are these TX-specific filtering bits valid for the RX channel configuration
register?

According to the hardware abstractions, UDMA_CHAN_CFG_FILT_EINFO and
UDMA_CHAN_CFG_FILT_PSWORDS map exclusively to the transmit channel's TCHAN_TCFG
register. Receive channels do not appear to have these configuration fields
in their CFG register.

Extended info presence for RX channels seems to be configured at the receive
flow level (using UDMA_FLOWRT_RFA_RX_EINFO_PRESENT), which is already handled
independently in k3_udma_glue_cfg_rx_flow(). Writing these TX-specific bits
to the RX channel here might set undefined or reserved bits and potentially
corrupt the RX channel hardware state.

> +
> +		return 0;
> +	}
> +
> +	req.nav_id = tisci_rm->tisci_dev_id;
>  	ret = tisci_rm->tisci_udmap_ops->rx_ch_cfg(tisci_rm->tisci, &req);
>  	if (ret)
>  		dev_err(rx_chn->common.dev, "rchan%d cfg failed %d\n",
> -			rx_chn->udma_rchan_id, ret);
> -
> +				rx_chn->udma_rchan_id, ret);
>  	return ret;
>  }

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261007102936.2402427-1-s-adivi@ti.com?part=19