Colin Cross wrote at Wednesday, February 23, 2011 10:38 AM: > > On Wed, Feb 23, 2011 at 9:29 AM, Stephen Warren <swarren@xxxxxxxxxx> wrote: > > tegra_dma_init currently simply bails out early if any initialization fails. > > This skips various data-structure initialization. In turn, this means that > > tegra_dma_allocate_channel can still hand out channels. In this case, when > > tegra_dma_free_channel is called, which calls tegra_dma_cancel, the walking > > on ch->list will OOPS since the list's next/prev pointers may still be > > NULL. > > > > To solve this: > > * Mark all possible channels as in-use before doing anything else in init. > > * Only mark a channel as free once all channel-related initialization has > > completed. > > > > This prevents allocate_channel from handing out uninitialized channels. > > > > There is still one small hole; allocate_channel can't check the usage array > > for the shared channel, since this channel is permanently marked in-use. > > This could be solved using an explicit "init OK" flag that allocate_channel > > could check. > > If we still need an init complete flag, why not skip this patch and > just add that? I tend to like the cleanup in this patch; it simplifies the channel_usage initialization. I'll let you make the call on whether to take this or not. I can certainly throw together a second patch, or modify this patch, to also use an init_ok flag to completely solve the shared channel case too though. -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
