lkml.org 
[lkml]   [2020]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [Patch v2 2/4] dmaengine: tegra: Add Tegra GPC DMA driver
From
Date
06.08.2020 16:56, Rajesh Gumasta пишет:
...
>>> +static const struct __maybe_unused dev_pm_ops
>> tegra_dma_dev_pm_ops = {
>>> + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_dma_pm_suspend,
>>> +tegra_dma_pm_resume) };
>>
>> Please explain why this is needed. All DMA should be stopped (not
>> paused) on system's suspend, shouldn't it?
> I have rechecked with HW verification team and they confirmed that after suspend, csr and channel registers will get reset hence on resume we need to restore back.
> Also GPCDMA does not support power gate as a unit.

But all registers are re-programmed on starting a DMA transfer, hence
why do you need to save-restore them on suspend-resume?

\
 
 \ /
  Last update: 2020-08-06 19:25    [W:0.171 / U:0.704 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site