Re: [PATCH v7 12/19] dmaengine: tegra-apb: Remove handling of unrealistic error condition

From: Jon Hunter
Date: Tue Feb 04 2020 - 06:52:50 EST



On 02/02/2020 22:28, Dmitry Osipenko wrote:
> The pending_sg_req list can't ever be empty because:
>
> 1. If it was empty, then handle_cont_sngl_cycle_dma_done() shall crash
> before of handle_continuous_head_request() invocation.
>
> 2. The handle_cont_sngl_cycle_dma_done() can't happen after stopping DMA.

By this you mean calling terminate_all?

> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/dma/tegra20-apb-dma.c | 6 ------
> 1 file changed, 6 deletions(-)
>
> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> index 62d181bd5e62..c7dc27ef1856 100644
> --- a/drivers/dma/tegra20-apb-dma.c
> +++ b/drivers/dma/tegra20-apb-dma.c
> @@ -564,12 +564,6 @@ static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
> {
> struct tegra_dma_sg_req *hsgreq;
>
> - if (list_empty(&tdc->pending_sg_req)) {
> - dev_err(tdc2dev(tdc), "DMA is running without req\n");
> - tegra_dma_stop(tdc);
> - return false;
> - }
> -
> /*
> * Check that head req on list should be in flight.
> * If it is not in flight then abort transfer as
>

There is also a list_empty() check in tdc_configure_next_head_desc()
which is also redundant and could be removed here as well.

Jon

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