Re: [PATCH v2] net: ethernet: ti: davinci_cpdma: fix warning "device driver frees DMA memory with different size"

[Grygorii Strashko]

On 04/12/2019 22:37, David Miller wrote:
> From: Grygorii Strashko <grygorii.strashko@xxxxxx>
> Date: Wed, 4 Dec 2019 18:50:29 +0200
>
> > @@ -1018,7 +1018,7 @@ static int cpdma_chan_submit_si(struct submit_info *si)
> >   	struct cpdma_chan		*chan = si->chan;
> >   	struct cpdma_ctlr		*ctlr = chan->ctlr;
> >   	int				len = si->len;
> > -	int				swlen = len;
> > +	int				swlen;
> >   	struct cpdma_desc __iomem	*desc;
> >   	dma_addr_t			buffer;
> >   	u32				mode;
> > @@ -1040,6 +1040,7 @@ static int cpdma_chan_submit_si(struct submit_info *si)
> >   		chan->stats.runt_transmit_buff++;
> >   	}
> >   
> > +	swlen = len;
> >   	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
> >   	cpdma_desc_to_port(chan, mode, si->directed);
> >   
> > --
> > 2.17.1
>
> Now there is no reason to keep a separate swlen variable.
>
> The integral value is always consumed as the length before the descriptor bits
> are added to it.
>
> Therefore you can just use 'len' everywhere in this function now.

Sry, but seems i can't, at least i can't just drop swlen.

Below in this function:
	writel_relaxed(0, &desc->hw_next);
	writel_relaxed(buffer, &desc->hw_buffer);
	writel_relaxed(len, &desc->hw_len);
	writel_relaxed(mode | len, &desc->hw_mode);
^^ here the "len" should be use

	writel_relaxed((uintptr_t)si->token, &desc->sw_token);
	writel_relaxed(buffer, &desc->sw_buffer);
	writel_relaxed(swlen, &desc->sw_len);
^^ and here "len"|CPDMA_DMA_EXT_MAP if (si->data_dma) [1]

	desc_read(desc, sw_len);

so additional if statement has to be added at [1] if "swlen" is dropped

--
Best regards,
grygorii