Re: [PATCH V2] dma: tegra: avoid channel lock up after free
From: Laxman Dewangan <ldewangan@nvidia.com>
Date: 2012-10-31 15:00:37
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From: Laxman Dewangan <ldewangan@nvidia.com>
Date: 2012-10-31 15:00:37
Also in:
lkml
On Tuesday 30 October 2012 04:50 AM, Dmitry Osipenko wrote:
Fixed channel "lock up" after free. Lock scenario: Channel 1 was allocated and prepared as slave_sg, used and freed. Now preparation of cyclic dma on channel 1 will fail with err "DMA configuration conflict" because tdc->isr_handler still selected to handle_once_dma_done. This happens because tegra_dma_abort_all() won't be called on channel freeing if pending list is empty or channel not busy. We need to clear isr_handler on channel freeing to avoid locking. Also I added small optimization to prepare functions, so current channel type checked before making allocations. Signed-off-by: Dmitry Osipenko<digetx@gmail.com> ---
Looks good to me. Acked-by: Laxman Dewangan <ldewangan@nvidia.com>