usb: musb: Check devctl status again for a spurious session request

On start-up, we can get a spurious session request interrupt with nothing
connected. After that the devctl session bit will silently clear, but the
musb hardware is never idled until a cable is plugged in, or the glue
layer module is reloaded.

Let's just check the session bit again in 3 seconds in peripheral mode
to catch the issue.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20210518150615.53464-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 8f09a38..71ae840 100644 (file)
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2055,6 +2055,15 @@ static void musb_pm_runtime_check_session(struct musb *musb)
                        dev_err(musb->controller, "Could not enable: %i\n",
                                error);
                musb->quirk_retries = 3;
+
+               /*
+                * We can get a spurious MUSB_INTR_SESSREQ interrupt on start-up
+                * in B-peripheral mode with nothing connected and the session
+                * bit clears silently. Check status again in 3 seconds.
+                */
+               if (devctl & MUSB_DEVCTL_BDEVICE)
+                       schedule_delayed_work(&musb->irq_work,
+                                             msecs_to_jiffies(3000));
        } else {
                musb_dbg(musb, "Allow PM with no session: %02x", devctl);
                pm_runtime_mark_last_busy(musb->controller);