diff options
Diffstat (limited to 'kernels/linux-libre-rt/0011-usb-musb-Fix-hardirq-safe-hardirq-unsafe-lock-order-.patch')
| -rw-r--r-- | kernels/linux-libre-rt/0011-usb-musb-Fix-hardirq-safe-hardirq-unsafe-lock-order-.patch | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/kernels/linux-libre-rt/0011-usb-musb-Fix-hardirq-safe-hardirq-unsafe-lock-order-.patch b/kernels/linux-libre-rt/0011-usb-musb-Fix-hardirq-safe-hardirq-unsafe-lock-order-.patch new file mode 100644 index 000000000..9c53526b9 --- /dev/null +++ b/kernels/linux-libre-rt/0011-usb-musb-Fix-hardirq-safe-hardirq-unsafe-lock-order-.patch @@ -0,0 +1,86 @@ +From b947f36e0453d0bc466fd88a883f3c4a50e6f6a1 Mon Sep 17 00:00:00 2001 +From: Tony Lindgren <tony@atomide.com> +Date: Fri, 30 Sep 2016 11:10:09 -0700 +Subject: [PATCH 11/14] usb: musb: Fix hardirq-safe hardirq-unsafe lock order + error + +If we configure musb with 2430 glue as a peripheral, and then rmmod +omap2430 module, we'll get the following error: + +[ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ] +... +rmmod/413 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: + (&phy->mutex){+.+.+.}, at: [<c04b9fd0>] phy_power_off+0x1c/0xb8 +[ 204.678710] + and this task is already holding: + (&(&musb->lock)->rlock){-.-...}, at: [<bf3a482c>] + musb_gadget_stop+0x24/0xec [musb_hdrc] +which would create a new lock dependency: + (&(&musb->lock)->rlock){-.-...} -> (&phy->mutex){+.+.+.} +... + +This is because some glue layers expect musb_platform_enable/disable +to be called with spinlock held, and 2430 glue layer has USB PHY on +the I2C bus using a mutex. + +We could fix the glue layers to take the spinlock, but we still have +a problem of musb_plaform_enable/disable being called in an unbalanced +manner. So that would still lead into USB PHY enable/disable related +problems for omap2430 glue layer. + +While it makes sense to only enable USB PHY when needed from PM point +of view, in this case we just can't do it yet without breaking things. +So let's just revert phy_enable/disable related changes instead and +reconsider this after we have fixed musb_platform_enable/disable to +be balanced. + +Fixes: a83e17d0f73b ("usb: musb: Improve PM runtime and phy handling +for 2430 glue layer") +Signed-off-by: Tony Lindgren <tony@atomide.com> +Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> +--- + drivers/usb/musb/omap2430.c | 7 ++----- + 1 file changed, 2 insertions(+), 5 deletions(-) + +diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c +index 0b4cec9..dae92de 100644 +--- a/drivers/usb/musb/omap2430.c ++++ b/drivers/usb/musb/omap2430.c +@@ -337,6 +337,7 @@ static int omap2430_musb_init(struct musb *musb) + } + musb->isr = omap2430_musb_interrupt; + phy_init(musb->phy); ++ phy_power_on(musb->phy); + + l = musb_readl(musb->mregs, OTG_INTERFSEL); + +@@ -373,8 +374,6 @@ static void omap2430_musb_enable(struct musb *musb) + struct musb_hdrc_platform_data *pdata = dev_get_platdata(dev); + struct omap_musb_board_data *data = pdata->board_data; + +- if (!WARN_ON(!musb->phy)) +- phy_power_on(musb->phy); + + omap2430_set_power(musb, true, glue->cable_connected); + +@@ -413,9 +412,6 @@ static void omap2430_musb_disable(struct musb *musb) + struct device *dev = musb->controller; + struct omap2430_glue *glue = dev_get_drvdata(dev->parent); + +- if (!WARN_ON(!musb->phy)) +- phy_power_off(musb->phy); +- + if (glue->status != MUSB_UNKNOWN) + omap_control_usb_set_mode(glue->control_otghs, + USB_MODE_DISCONNECT); +@@ -429,6 +425,7 @@ static int omap2430_musb_exit(struct musb *musb) + struct omap2430_glue *glue = dev_get_drvdata(dev->parent); + + omap2430_low_level_exit(musb); ++ phy_power_off(musb->phy); + phy_exit(musb->phy); + musb->phy = NULL; + cancel_work_sync(&glue->omap_musb_mailbox_work); +-- +2.10.0 + |