diff options
| author | Weitao Wango <WeitaoWang-oc@zhaoxin.com> | 2022-03-24 15:17:35 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-21 19:53:53 +0300 |
| commit | f085bd4bfe0907ce2fad2c787fc65871ec5ca6d6 (patch) | |
| tree | 77617e99a6b76fb214b5dd767c35c9efa2010540 /drivers/usb/host/ehci-hcd.c | |
| parent | 8d084b2eae7fc5fcfc9f143cd7321a88e1cd76aa (diff) | |
| download | linux-f085bd4bfe0907ce2fad2c787fc65871ec5ca6d6.tar.xz | |
USB: Fix ehci infinite suspend-resume loop issue in zhaoxin
In zhaoxin platform, some ehci projects will latch a wakeup signal
internal when plug in a device on port during system S0. This wakeup
signal will turn on when ehci runtime suspend, which will trigger a
system control interrupt that will resume ehci back to D0. As no
device connect, ehci will be set to runtime suspend and turn on the
internal latched wakeup signal again. It will cause a suspend-resume
loop and generate system control interrupt continuously.
Fixed this issue by clear wakeup signal latched in ehci internal when
ehci resume callback is called.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Weitao Wang <WeitaoWang-oc@zhaoxin.com>
Link: https://lore.kernel.org/r/20220324121735.3803-1-WeitaoWang-oc@zhaoxin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/ehci-hcd.c')
| -rw-r--r-- | drivers/usb/host/ehci-hcd.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 3d82e0b853be..684164fa9716 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -1103,6 +1103,26 @@ static void ehci_remove_device(struct usb_hcd *hcd, struct usb_device *udev) #ifdef CONFIG_PM +/* Clear wakeup signal locked in zhaoxin platform when device plug in. */ +static void ehci_zx_wakeup_clear(struct ehci_hcd *ehci) +{ + u32 __iomem *reg = &ehci->regs->port_status[4]; + u32 t1 = ehci_readl(ehci, reg); + + t1 &= (u32)~0xf0000; + t1 |= PORT_TEST_FORCE; + ehci_writel(ehci, t1, reg); + t1 = ehci_readl(ehci, reg); + msleep(1); + t1 &= (u32)~0xf0000; + ehci_writel(ehci, t1, reg); + ehci_readl(ehci, reg); + msleep(1); + t1 = ehci_readl(ehci, reg); + ehci_writel(ehci, t1 | PORT_CSC, reg); + ehci_readl(ehci, reg); +} + /* suspend/resume, section 4.3 */ /* These routines handle the generic parts of controller suspend/resume */ @@ -1154,6 +1174,9 @@ int ehci_resume(struct usb_hcd *hcd, bool force_reset) if (ehci->shutdown) return 0; /* Controller is dead */ + if (ehci->zx_wakeup_clear_needed) + ehci_zx_wakeup_clear(ehci); + /* * If CF is still set and reset isn't forced * then we maintained suspend power. |