Commit 454f83d5 authored Nov 21, 2016 by Hans de Goede Committed by Greg Kroah-Hartman Nov 21, 2016

musb: sunxi: Force session end on babble errors in host-mode



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 <hdegoede@redhat.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent d24b63ab

drivers/usb/musb/sunxi.c

+15 −0

Original line number	Diff line number	Diff line
		@@ -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,

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