usb: musb: finish suspend/reset work independently from musb_hub_control()

Currently, resume and reset is completed when the USB core calls back
the root hub, asking for the port's state. This results in
unpredictable timing of state assertion, which in turn renders some
USB devices unusable after resume.

Fix this by moving the logic to end the reset and suspend state out of
musb_hub_control() into separate functions called from delayed workers.
GetPortStatus only reports the current state now, without taking any
real action.

The rh_timeout variable is kept in order to define a minimum time gap
between reset and resume only.

FWIW, in my case, a Verbatim "STORE N GO" mass storage device won't
resume cleanly without this patch.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 23 insertions, 2 deletions

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 1ecdb94f3812..0e7f4a00ca7b 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -478,8 +478,8 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb,
 				musb->port1_status |=
 						(USB_PORT_STAT_C_SUSPEND << 16)
 						| MUSB_PORT_STAT_RESUME;
-				musb->rh_timer = jiffies
-						+ msecs_to_jiffies(20);
+				schedule_delayed_work(
+					&musb->finish_resume_work, 20);
 
 				musb->xceiv->state = OTG_STATE_A_HOST;
 				musb->is_active = 1;
@@ -1813,6 +1813,21 @@ static void musb_free(struct musb *musb)
 	musb_host_free(musb);
 }
 
+static void musb_deassert_reset(struct work_struct *work)
+{
+	struct musb *musb;
+	unsigned long flags;
+
+	musb = container_of(work, struct musb, deassert_reset_work.work);
+
+	spin_lock_irqsave(&musb->lock, flags);
+
+	if (musb->port1_status & USB_PORT_STAT_RESET)
+		musb_port_reset(musb, false);
+
+	spin_unlock_irqrestore(&musb->lock, flags);
+}
+
 /*
  * Perform generic per-controller initialization.
  *
@@ -1897,6 +1912,8 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
 
 	/* Init IRQ workqueue before request_irq */
 	INIT_WORK(&musb->irq_work, musb_irq_work);
+	INIT_DELAYED_WORK(&musb->deassert_reset_work, musb_deassert_reset);
+	INIT_DELAYED_WORK(&musb->finish_resume_work, musb_host_finish_resume);
 
 	/* setup musb parts of the core (especially endpoints) */
 	status = musb_core_init(plat->config->multipoint
@@ -1990,6 +2007,8 @@ fail4:
 
 fail3:
 	cancel_work_sync(&musb->irq_work);
+	cancel_delayed_work_sync(&musb->finish_resume_work);
+	cancel_delayed_work_sync(&musb->deassert_reset_work);
 	if (musb->dma_controller)
 		dma_controller_destroy(musb->dma_controller);
 fail2_5:
@@ -2053,6 +2072,8 @@ static int musb_remove(struct platform_device *pdev)
 		dma_controller_destroy(musb->dma_controller);
 
 	cancel_work_sync(&musb->irq_work);
+	cancel_delayed_work_sync(&musb->finish_resume_work);
+	cancel_delayed_work_sync(&musb->deassert_reset_work);
 	musb_free(musb);
 	device_init_wakeup(dev, 0);
 	return 0;