Commit d9140a0d authored by Phuong Nguyen's avatar Phuong Nguyen Committed by Vinod Koul

dmaengine: usb-dmac: Make DMAC system sleep callbacks explicit

This commit fixes the issue that USB-DMAC hangs silently after system
resumes on R-Car Gen3 hence renesas_usbhs will not work correctly
when using USB-DMAC for bulk transfer e.g. ethernet or serial
gadgets.

The issue can be reproduced by these steps:
 1. modprobe g_serial
 2. Suspend and resume system.
 3. connect a usb cable to host side
 4. Transfer data from Host to Target
 5. cat /dev/ttyGS0 (Target side)
 6. echo "test" > /dev/ttyACM0 (Host side)

The 'cat' will not result anything. However, system still can work
normally.

Currently, USB-DMAC driver does not have system sleep callbacks hence
this driver relies on the PM core to force runtime suspend/resume to
suspend and reinitialize USB-DMAC during system resume. After
the commit 17218e00 ("PM / genpd: Stop/start devices without
pm_runtime_force_suspend/resume()"), PM core will not force
runtime suspend/resume anymore so this issue happens.

To solve this, make system suspend resume explicit by using
pm_runtime_force_{suspend,resume}() as the system sleep callbacks.
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS() is used to make sure USB-DMAC
suspended after and initialized before renesas_usbhs."
Signed-off-by: default avatarPhuong Nguyen <phuong.nguyen.xw@renesas.com>
Signed-off-by: default avatarHiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Cc: <stable@vger.kernel.org> # v4.16+
[shimoda: revise the commit log and add Cc tag]
Signed-off-by: default avatarYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent bfeffd15
...@@ -694,6 +694,8 @@ static int usb_dmac_runtime_resume(struct device *dev) ...@@ -694,6 +694,8 @@ static int usb_dmac_runtime_resume(struct device *dev)
#endif /* CONFIG_PM */ #endif /* CONFIG_PM */
static const struct dev_pm_ops usb_dmac_pm = { static const struct dev_pm_ops usb_dmac_pm = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume, SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume,
NULL) NULL)
}; };
......
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