Re: [PATCH v2 02/53] dmaengine: Make channel allocation callbacks optional

From: Laurent Pinchart
Date: Thu Oct 16 2014 - 06:35:51 EST


Hi Maxime,

Thank you for the patch.

On Thursday 16 October 2014 12:17:01 Maxime Ripard wrote:
> Nowadays, some drivers don't have anything in there channel allocation
> callbacks anymore.
>
> Remove the BUG_ON if those callbacks aren't implemented, in order to allow
> drivers to not implement them.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/dma/dmaengine.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index d5d30ed863ce..cfcb181b1184 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -817,8 +817,6 @@ int dma_async_device_register(struct dma_device *device)
> BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
> !device->device_prep_interleaved_dma);
>
> - BUG_ON(!device->device_alloc_chan_resources);
> - BUG_ON(!device->device_free_chan_resources);
> BUG_ON(!device->device_tx_status);
> BUG_ON(!device->device_issue_pending);
> BUG_ON(!device->dev);

This will make dma_chan_get() or dma_chan_put() crash if the alloc or free
functions are not implemented.

--
Regards,

Laurent Pinchart

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