Re: [RFC] dmaengine: omap-dma: Allow DMA controller to prefetch data

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Oct 18, 2012 at 03:20:46PM -0700, Mark A. Greer wrote:
> This patch seems fairly stable but I've only tested omap-sham (crypto)
> and omap_hsmmc (mmc) on an am37x EVM.  I also enabled burst mode but
> that made the system unstable when exercising either omap-sham or
> omap_hsmmc.  I'm unaware of any errata that would make this an unwanted
> modification but I haven't checked all of the SoCs.  Are there other
> reasons that this should be applied??

It definitely needs checking with audio, because it will affect the
pointer position in relation to audio output, and it will have an
effect on how much audio data is lost over a pause/resume event.

Unfortunately, the OMAP DMA hardware has no way to do a proper "pause",
it can only do a "stop" which involves dumping its FIFOs on the floor
in the case of anything but a DEV->MEM transfer.  So the more data
held in the DMA hardware, the more is lost on pause.
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Arm (vger)]     [ARM Kernel]     [ARM MSM]     [Linux Tegra]     [Linux WPAN Networking]     [Linux Wireless Networking]     [Maemo Users]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Trails]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux