[PATCH v6 0/5] add runtime suspend/resume support

From: joy . zou

Date: Wed Jul 01 2026 - 05:26:29 EST


Clean up driver FLAGs and introduce runtime suspend and resume support for
FSL eDMA.

Signed-off-by: Joy Zou <joy.zou@xxxxxxxxxxx>
---
Changes in V6:
- add synchronize_irq() before disabling the channel clock in fsl_edma_chan_runtime_suspend()
per AI review comments.
- add pm_runtime_get_if_active() in interrupt handlers to ensure registers can be accessed
correctly per AI review comments.
- remove manual fsl_edma3_detach_pd() call when device_link_add() fails. The devres
framework will handle cleanup automatically on probe failure per AI review comments.
- clear fsl_chan->pd_dev_link after freeing the device link to prevent potential
use-after-free issues per AI review comments..
- move fsl_edma->drvdata->setup_irq() atfer edma engine pm_runtime_resume_and_get().
- replace devm_clk_bulk_get_optional_enable() with devm_clk_get_optional()
and clk_bulk_prepare_enable() in order to use runtime PM for power
management later.
- replace devm_clk_get_optional_enable() with devm_clk_get_optional()
and devm_clk_prepare_enable() in order to use runtime PM for power
management later for patch #1 and #2.
- add new patch #5 fix use-after-free issue per AI review comments.
- modify the commit message for patch #1,#2 and #3.
- add Reviewed-by tag for patch #1,#2 and #3.
- Link to v5: https://lore.kernel.org/r/20260513-b4-b4-edma-runtime-opt-v5-0-1e595bfb8423@xxxxxxx

Changes in V5:
- add three new patches, two of which replace devm_clk_get_enabled() with devm_clk_get_optional_enabled(),
and the other convert to clk bulk API.
- remove unnecessary flags FSL_EDMA_DRV_HAS_CHCLK and FSL_EDMA_DRV_HAS_DMACLK.
- remove redundant clk_disable_unprepare() due to the pm_runtime_put_sync_suspend() added.
- use devm_pm_runtime_enable() to replace pm_runtime_enable() and add return value check.
- add return value check for pm_runtime_get_sync().
- replace pm_runtime_get_sync() with pm_runtime_resume_and_get().
- replace DMAMUX clock handling with bulk clock API for edma engine runtime suspend/resume.
- remove dev_pm_domain_detach() when device_link_add() fail because the fsl_edma3_detach_pd()
also call dev_pm_domain_detach().
- remove device_link_add() DL_FLAG_RPM_ACTIVE flag and pm_runtime_put_sync_suspend().
- add clk_bulk_disable_unprepare() for clk_prepare_enable() fail in fsl_edma_runtime_resume().
- remove the extra space before RUNTIME_PM_OPS.
- add skip channel comments for system suspend.
- add clk_disable_unprepare() for dmaclk at the end of probe function.
- add clk_bulk_disable_unprepare() for muxclk at the end of probe function.
- Link to v4: https://lore.kernel.org/imx/20251017-b4-edma-runtime-v4-1-87c64dd30229@xxxxxxx/

Changes for V4:
- fix a typo dmaegnine/dmaengine in the subject.
- Link to v3: https://lore.kernel.org/imx/20250912-b4-edma-runtime-v3-1-be22f7161745@xxxxxxx/

Changes for V3:
- rebased onto commit 8f21d9da4670 ("Add linux-next specific files for 20250911")
to align with latest changes.
- Remove pm_runtime_dont_use_autosuspend() from fsl_edma3_detach_pd().
because the autosuspend is not used.
- Move some edma channel registers initialization after the chan_dev
pm_runtime_enable().
- Add clk_prepare_enable() return check in fsl_edma_runtime_resume.
- Add flag FSL_EDMA_DRV_HAS_DMACLK check in fsl_edma_runtime_resume/suspend().
- Link to v2: https://lore.kernel.org/imx/20241226052643.1951886-1-joy.zou@xxxxxxx/

Changes for V2:
- drop ret from fsl_edma_chan_runtime_suspend().
- drop ret from fsl_edma_chan_runtime_resume() and return clk_prepare_enable().
- add review tag
- Link to v1: https://lore.kernel.org/imx/20241220021109.2102294-1-joy.zou@xxxxxxx/

To: Frank Li <Frank.Li@xxxxxxx>
To: Vinod Koul <vkoul@xxxxxxxxxx>
To: Joe Hattori <joe@xxxxxxxxxxxxxxxxxxxxx>
Cc: Frank Li <Frank.Li@xxxxxxxxxx>
Cc: imx@xxxxxxxxxxxxxxx
Cc: dmaengine@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

---
Joy Zou (5):
dmaengine: fsl-edma: use devm_clk_get_optional() for channel clock
dmaengine: fsl-edma: use devm_clk_get_optional() for DMA engine clock
dmaengine: fsl-edma: convert DMAMUX clock handling to bulk clock API
dmaengine: fsl-edma: add runtime suspend/resume support
dmaengine: fsl-edma: fix use-after-free after dev_pm_domain_detach()

drivers/dma/fsl-edma-common.c | 14 +-
drivers/dma/fsl-edma-common.h | 4 +-
drivers/dma/fsl-edma-main.c | 305 +++++++++++++++++++++++++++++++-----------
3 files changed, 234 insertions(+), 89 deletions(-)
---
base-commit: f7af91adc230aa99e23330ecf85bc9badd9780ad
change-id: 20260617-b4-edma-runtime-opt-2b14d269bcee

Best regards,
--
Joy Zou <joy.zou@xxxxxxxxxxx>