lkml.org 
[lkml]   [2012]   [Oct]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH V2] dma: tegra: avoid channel lock up after free
On 10/29/2012 05:20 PM, 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.

Reviewed-by: Stephen Warren <swarren@nvidia.com>

I believe this looks OK. However, I would like Laxman to also ack/review
this since he wrote the driver.


\
 
 \ /
  Last update: 2012-10-30 19:21    [W:0.080 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site