diff options
| author | Claudiu Beznea <claudiu.beznea@microchip.com> | 2023-02-14 17:18:24 +0200 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2023-04-12 23:18:44 +0530 |
| commit | 7c5eb63d16b01c202aaa95f374ae15a807745a73 (patch) | |
| tree | eae2f2fb8495d27fd784fc9cdd68f1e2da6b93e8 | |
| parent | 44fe8440bda545b5d167329df88c47609a645168 (diff) | |
dmaengine: at_xdmac: restore the content of grws register
In case the system suspends to a deep sleep state where power to DMA
controller is cut-off we need to restore the content of GRWS register.
This is a write only register and writing bit X tells the controller
to suspend read and write requests for channel X. Thus set GRWS before
restoring the content of GE (Global Enable) regiter.
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230214151827.1050280-5-claudiu.beznea@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
| -rw-r--r-- | drivers/dma/at_xdmac.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index fa1e2e0da02f..34c004a4b23c 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -2211,6 +2211,15 @@ static int __maybe_unused atmel_xdmac_resume(struct device *dev) return ret; at_xdmac_device_resume_internal(atchan); } + + /* + * We may resume from a deep sleep state where power + * to DMA controller is cut-off. Thus, restore the + * suspend state of channels set though dmaengine API. + */ + else if (at_xdmac_chan_is_paused(atchan)) + at_xdmac_device_pause_set(atxdmac, atchan); + at_xdmac_chan_write(atchan, AT_XDMAC_CNDA, atchan->save_cnda); at_xdmac_chan_write(atchan, AT_XDMAC_CNDC, atchan->save_cndc); at_xdmac_chan_write(atchan, AT_XDMAC_CIE, atchan->save_cim); |