4.4-stable review patch. If anyone has any objections, please let me know.
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From: Phuong Nguyen phuong.nguyen.xw@renesas.com
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 phuong.nguyen.xw@renesas.com Signed-off-by: Hiroyuki 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: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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 @@ -700,6 +700,8 @@ 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) };