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

Phuong Nguyen · vinodkoul · commit d9140a0da4a2 · 2019-01-20T16:29:52.000+05:30
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 17218e0 ("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>
diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
@@ -694,6 +694,8 @@ static int usb_dmac_runtime_resume(struct device *dev)
 #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)
 };
