4.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Phuong Nguyen <[email protected]> commit d9140a0da4a230a03426d175145989667758aa6a upstream. 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 17218e0092f8 ("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: Phuong Nguyen <[email protected]> Signed-off-by: Hiroyuki Yokoyama <[email protected]> Cc: <[email protected]> # v4.16+ [shimoda: revise the commit log and add Cc tag] Signed-off-by: Yoshihiro Shimoda <[email protected]> Signed-off-by: Vinod Koul <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/dma/sh/usb-dmac.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/dma/sh/usb-dmac.c +++ b/drivers/dma/sh/usb-dmac.c @@ -697,6 +697,8 @@ static int usb_dmac_runtime_resume(struc #endif /* CONFIG_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, NULL) };
