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authorDaniel Glöckner <dg@emlix.com>2018-05-14 09:40:05 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-06-26 08:08:06 +0800
commitc4f24a093f02bc43a602c08550d828ce34477380 (patch)
treeb67bea8584a6a815659cf1a9542f754ce5e58f96
parent42ff36e9cb95662ff8a0a0ac1aea54f386068fa4 (diff)
usb: musb: fix remote wakeup racing with suspend
[ Upstream commit ebc3dd688cd988754a304147753b13e58de1b5a1 ] It has been observed that writing 0xF2 to the power register while it reads as 0xF4 results in the register having the value 0xF0, i.e. clearing RESUME and setting SUSPENDM in one go does not work. It might also violate the USB spec to transition directly from resume to suspend, especially when not taking T_DRSMDN into account. But this is what happens when a remote wakeup occurs between SetPortFeature USB_PORT_FEAT_SUSPEND on the root hub and musb_bus_suspend being called. This commit returns -EBUSY when musb_bus_suspend is called while remote wakeup is signalled and thus avoids to reset the RESUME bit. Ignoring this error when musb_port_suspend is called from musb_hub_control is ok. Signed-off-by: Daniel Glöckner <dg@emlix.com> Signed-off-by: Bin Liu <b-liu@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/musb/musb_host.c5
-rw-r--r--drivers/usb/musb/musb_host.h7
-rw-r--r--drivers/usb/musb/musb_virthub.c25
3 files changed, 24 insertions, 13 deletions
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index e2bc91585b4f..19b5f08cb423 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -2554,8 +2554,11 @@ static int musb_bus_suspend(struct usb_hcd *hcd)
{
struct musb *musb = hcd_to_musb(hcd);
u8 devctl;
+ int ret;
- musb_port_suspend(musb, true);
+ ret = musb_port_suspend(musb, true);
+ if (ret)
+ return ret;
if (!is_host_active(musb))
return 0;
diff --git a/drivers/usb/musb/musb_host.h b/drivers/usb/musb/musb_host.h
index 7bbf01bf4bb0..54d02ed032df 100644
--- a/drivers/usb/musb/musb_host.h
+++ b/drivers/usb/musb/musb_host.h
@@ -92,7 +92,7 @@ extern void musb_host_rx(struct musb *, u8);
extern void musb_root_disconnect(struct musb *musb);
extern void musb_host_resume_root_hub(struct musb *musb);
extern void musb_host_poke_root_hub(struct musb *musb);
-extern void musb_port_suspend(struct musb *musb, bool do_suspend);
+extern int musb_port_suspend(struct musb *musb, bool do_suspend);
extern void musb_port_reset(struct musb *musb, bool do_reset);
extern void musb_host_finish_resume(struct work_struct *work);
#else
@@ -124,7 +124,10 @@ static inline void musb_root_disconnect(struct musb *musb) {}
static inline void musb_host_resume_root_hub(struct musb *musb) {}
static inline void musb_host_poll_rh_status(struct musb *musb) {}
static inline void musb_host_poke_root_hub(struct musb *musb) {}
-static inline void musb_port_suspend(struct musb *musb, bool do_suspend) {}
+static inline int musb_port_suspend(struct musb *musb, bool do_suspend)
+{
+ return 0;
+}
static inline void musb_port_reset(struct musb *musb, bool do_reset) {}
static inline void musb_host_finish_resume(struct work_struct *work) {}
#endif
diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c
index 61b5f1c3c5bc..71678a487be2 100644
--- a/drivers/usb/musb/musb_virthub.c
+++ b/drivers/usb/musb/musb_virthub.c
@@ -73,14 +73,14 @@ void musb_host_finish_resume(struct work_struct *work)
spin_unlock_irqrestore(&musb->lock, flags);
}
-void musb_port_suspend(struct musb *musb, bool do_suspend)
+int musb_port_suspend(struct musb *musb, bool do_suspend)
{
struct usb_otg *otg = musb->xceiv->otg;
u8 power;
void __iomem *mbase = musb->mregs;
if (!is_host_active(musb))
- return;
+ return 0;
/* NOTE: this doesn't necessarily put PHY into low power mode,
* turning off its clock; that's a function of PHY integration and
@@ -91,16 +91,20 @@ void musb_port_suspend(struct musb *musb, bool do_suspend)
if (do_suspend) {
int retries = 10000;
- power &= ~MUSB_POWER_RESUME;
- power |= MUSB_POWER_SUSPENDM;
- musb_writeb(mbase, MUSB_POWER, power);
+ if (power & MUSB_POWER_RESUME)
+ return -EBUSY;
- /* Needed for OPT A tests */
- power = musb_readb(mbase, MUSB_POWER);
- while (power & MUSB_POWER_SUSPENDM) {
+ if (!(power & MUSB_POWER_SUSPENDM)) {
+ power |= MUSB_POWER_SUSPENDM;
+ musb_writeb(mbase, MUSB_POWER, power);
+
+ /* Needed for OPT A tests */
power = musb_readb(mbase, MUSB_POWER);
- if (retries-- < 1)
- break;
+ while (power & MUSB_POWER_SUSPENDM) {
+ power = musb_readb(mbase, MUSB_POWER);
+ if (retries-- < 1)
+ break;
+ }
}
musb_dbg(musb, "Root port suspended, power %02x", power);
@@ -137,6 +141,7 @@ void musb_port_suspend(struct musb *musb, bool do_suspend)
schedule_delayed_work(&musb->finish_resume_work,
msecs_to_jiffies(USB_RESUME_TIMEOUT));
}
+ return 0;
}
void musb_port_reset(struct musb *musb, bool do_reset)