Re: [PATCH] i2c: at91: use dma safe buffers

[Codrin.Ciubotariu]

On 03.03.2022 18:17, Michael Walle wrote:
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> 
> The supplied buffer might be on the stack and we get the following error
> message:
> [    3.312058] at91_i2c e0070600.i2c: rejecting DMA map of vmalloc memory
> 
> Use i2c_{get,put}_dma_safe_msg_buf() to get a DMA-able memory region if
> necessary.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Michael Walle <michael@xxxxxxxx>

Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>

> ---
> 
> I'm not sure if or which Fixes: tag I should add to this patch. The issue
> seems to be since a very long time, but nobody seem to have triggered it.
> FWIW, I'm using the sff,sfp driver, which triggers this.

I think it should be:
Fixes: 60937b2cdbf9 ("i2c: at91: add dma support")

> +       if (dev->use_dma) {
> +               dma_buf = i2c_get_dma_safe_msg_buf(m_start, 1);

If you want, you could just dev->buf = i2c_get_dma_safe...

> +               if (!dma_buf) {
> +                       ret = -ENOMEM;
> +                       goto out;
> +               }
> +               dev->buf = dma_buf;

Thanks!