The current (empty) system sleep callbacks rely on the PM core to force
a runtime resume to reinitialize the DMAC registers during system
resume. Without a reinitialization, e.g. SCIF DMA will hang silently
after a system resume on R-Car Gen3.
Make this explicit by using pm_runtime_force_{suspend,resume}() as the
system sleep callbacks instead. Use SET_LATE_SYSTEM_SLEEP_PM_OPS() as
DMA engines must be initialized before all DMA slave devices.
Suggested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
This is a dependency for "[PATCH 1/2] PM / genpd: Stop/start devices
without pm_runtime_force_suspend/resume()"
(https://www.spinics.net/lists/kernel/msg2696802.html), so perhaps it
makes most sense if Rafael takes it through the PM tree?
Thanks!
---
drivers/dma/sh/rcar-dmac.c | 24 +++++++-----------------
1 file changed, 7 insertions(+), 17 deletions(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index fb06b193ad252086..06e4e604eebb79f6 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1657,22 +1657,6 @@ static struct dma_chan *rcar_dmac_of_xlate(struct of_phandle_args *dma_spec,
* Power management
*/
-#ifdef CONFIG_PM_SLEEP
-static int rcar_dmac_sleep_suspend(struct device *dev)
-{
- /*
- * TODO: Wait for the current transfer to complete and stop the device.
- */
- return 0;
-}
-
-static int rcar_dmac_sleep_resume(struct device *dev)
-{
- /* TODO: Resume transfers, if any. */
- return 0;
-}
-#endif
-
#ifdef CONFIG_PM
static int rcar_dmac_runtime_suspend(struct device *dev)
{
@@ -1688,7 +1672,13 @@ static int rcar_dmac_runtime_resume(struct device *dev)
#endif
static const struct dev_pm_ops rcar_dmac_pm = {
- SET_SYSTEM_SLEEP_PM_OPS(rcar_dmac_sleep_suspend, rcar_dmac_sleep_resume)
+ /*
+ * TODO for system sleep/resume:
+ * - Wait for the current transfer to complete and stop the device,
+ * - Resume transfers, if any.
+ */
+ SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(rcar_dmac_runtime_suspend, rcar_dmac_runtime_resume,
NULL)
};
--
2.7.4
