Commit 7c5eb63d authored by Claudiu Beznea's avatar Claudiu Beznea Committed by Vinod Koul
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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: e1f7c9ee ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230214151827.1050280-5-claudiu.beznea@microchip.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 44fe8440

drivers/dma/at_xdmac.c

+9 −0
Original line number Diff line number Diff line
@@ -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);