[Linaro-mm-sig] Re: [PATCH] i2c: at91: use dma safe buffers

On 05.04.2022 12:38, Michael Walle wrote:

Am 2022-04-05 11:23, schrieb Codrin.Ciubotariu@microchip.com:

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+       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...

But where is the error handling in that case? dev->buf will be NULL, which is eventually passed to dma_map_single().

Also, I need the dma_buf for the i2c_put_dma_safe_msg_buf() call anyway, because dev->buf will be modified during processing.

You still: if (!dev->buf) { ret = -ENOMEM; goto out; }

So, at91_do_twi_transfer()/dma_map_single() will not be called.

Best regards, Codrin