phy_sun4i_usb: set_mode: Allow using set_mode to force end the current session

The musb core already handles babble interrupts, so the sunxi glue having its own custom handling is redundant.

Signed-off-by Hans de Goede <[email protected]>

---
Changes in v2:
-This is a new patch in v2 of this patch series
Changes in v3:

(quoted diff) +0 -2

-Improve commit msg
---
 drivers/usb/musb/sunxi.c | 10 ----------
 1 file changed, 10 deletions(-)

drivers/usb/musb/sunxi.c +0 -10

index 1408245..82eba92 100644
@@ -186,16 +186,6 @@ static irqreturn_t sunxi_musb_interrupt(int irq, void *__hci)
 	if (musb->int_usb)
 		writeb(musb->int_usb, musb->mregs + SUNXI_MUSB_INTRUSB);
 
-	/*
-	 * sunxi musb often signals babble on low / full speed device
-	 * disconnect, without ever raising MUSB_INTR_DISCONNECT, since
-	 * normally babble never happens treat it as disconnect.
-	 */
-	if ((musb->int_usb & MUSB_INTR_BABBLE) && is_host_active(musb)) {
-		musb->int_usb &= ~MUSB_INTR_BABBLE;
-		musb->int_usb |= MUSB_INTR_DISCONNECT;
-	}
-
 	if ((musb->int_usb & MUSB_INTR_RESET) && !is_host_active(musb)) {
 		/* ep0 FADDR must be 0 when (re)entering peripheral mode */
 		musb_ep_select(musb->mregs, 0);

Signature · 1 line

2.9.3

The sunxi musb has a bug where sometimes it will generate a babble error on device disconnect instead of a disconnect irq. When this happens the musb-controller switches from host mode to device mode (it clears MUSB_DEVCTL_SESSION and sets MUSB_DEVCTL_BDEVICE) and gets stuck in this state.

Clearing this requires reporting Vbus low for 200 or more ms, but on some devices Vbus is simply always high (host-only mode, no Vbus control).

This commit adds a sunxi_musb_recover() callback which makes sunxi_musb_work call phy_set_mode with the current mode, which will force end the current session.

This fixes the musb controller getting stuck in this state on systems without Vbus control; and also fixes the need to unplug the usb-b -> usb-a cable to get out of this state on systems with Vbus control.

Signed-off-by Hans de Goede <[email protected]>

---
Changes in v2:

(quoted diff) +0 -3

-Use musb_platform_recover callback instead of using DYI code in the
 interrupt handler
-Call phy_set_mode with the current mode instead of adding a new custom
 sunxi phy callback
---
 drivers/usb/musb/sunxi.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

drivers/usb/musb/sunxi.c +15 -0

index 82eba92..d0be0ea 100644
@@ -380,6 +380,20 @@ static int sunxi_musb_set_mode(struct musb *musb, u8 mode)
 	return 0;
 }
 
+static int sunxi_musb_recover(struct musb *musb)
+{
+	struct sunxi_glue *glue = dev_get_drvdata(musb->controller->parent);
+
+	/*
+	 * Schedule a phy_set_mode with the current glue->phy_mode value,
+	 * this will force end the current session.
+	 */
+	set_bit(SUNXI_MUSB_FL_PHY_MODE_PEND, &glue->flags);
+	schedule_work(&glue->work);
+
+	return 0;
+}
+
 /*
  * sunxi musb register layout
  * 0x00 - 0x17	fifo regs, 1 long per fifo

@@ -608,6 +622,7 @@ static const struct musb_platform_ops sunxi_musb_ops = {
 	.dma_init	= sunxi_musb_dma_controller_create,
 	.dma_exit	= sunxi_musb_dma_controller_destroy,
 	.set_mode	= sunxi_musb_set_mode,
+	.recover	= sunxi_musb_recover,
 	.set_vbus	= sunxi_musb_set_vbus,
 	.pre_root_reset_end = sunxi_musb_pre_root_reset_end,
 	.post_root_reset_end = sunxi_musb_post_root_reset_end,

Signature · 1 line

2.9.3

The sunxi musb has a bug where sometimes it will generate a babble error on device disconnect instead of a disconnect irq. When this happens the musb-controller switches from host mode to device mode (it clears MUSB_DEVCTL_SESSION and sets MUSB_DEVCTL_BDEVICE) and gets stuck in this state.

Clearing this requires reporting Vbus low for 200 or more ms, but on some devices Vbus is simply always high (host-only mode, no Vbus control).

This commit modifies sun4i_usb_phy_set_mode so that it will force end the current session when called with the current mode, before this commit calling set_mode with the current mode was a nop since id_det would stay the same resulting in the detect_work not doing anything.

This allows the sunxi-musb glue to use sun4i_usb_phy_set_mode to force end the current session without changing the mode, to fixup the stuck state after a babble error.

Signed-off-by Hans de Goede <[email protected]>

---
Changes in v2:
-New patch in v2 of this series replacing the
"phy-sun4i-usb: Add sun4i_usb_phy_force_session_end() function" from v1
Changes in v3:

(quoted diff) +0 -2

-Fix dev_info so that it prints the new-mode instead of the old one
---
 drivers/phy/phy-sun4i-usb.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

drivers/phy/phy-sun4i-usb.c +10 -4

index 43c0d98..cbd338d 100644
@@ -437,25 +437,31 @@ static int sun4i_usb_phy_set_mode(struct phy *_phy, enum phy_mode mode)
 {
 	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
 	struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
+	int new_mode;
 
 	if (phy->index != 0)
 		return -EINVAL;
 
 	switch (mode) {
 	case PHY_MODE_USB_HOST:
-		data->dr_mode = USB_DR_MODE_HOST;
+		new_mode = USB_DR_MODE_HOST;
 		break;
 	case PHY_MODE_USB_DEVICE:
-		data->dr_mode = USB_DR_MODE_PERIPHERAL;
+		new_mode = USB_DR_MODE_PERIPHERAL;
 		break;
 	case PHY_MODE_USB_OTG:
-		data->dr_mode = USB_DR_MODE_OTG;
+		new_mode = USB_DR_MODE_OTG;
 		break;
 	default:
 		return -EINVAL;
 	}
 
-	dev_info(&_phy->dev, "Changing dr_mode to %d\n", (int)data->dr_mode);
+	if (new_mode != data->dr_mode) {
+		dev_info(&_phy->dev, "Changing dr_mode to %d\n", new_mode);
+		data->dr_mode = new_mode;
+	}
+
+	data->id_det = -1; /* Force reprocessing of id */
 	data->force_session_end = true;
 	queue_delayed_work(system_wq, &data->detect, 0);