From 5bf0ea60cf348a8cd657e34306b148a4ebb5f22a Mon Sep 17 00:00:00 2001 From: Tony LIU Date: Wed, 30 May 2012 13:56:38 +0800 Subject: [PATCH] ENGR00211686 mx6 usb: system crash after suspend/resume - the pre-condition of this issue is: 1. usb gadget must be probed before usb host 2. usb otg must be in host mode - the root cause of this issue is because of the issue of week 2p5, a vbus change interrupt will be issued when system enter into DSM, which will cause system exit DSM, so we have a walk aroud to disable usb vbus change interrupt when system enter into DSM. But this walk around just provent the interrupt generating, the vbus change status is still on. When usb gadget is probed, the vbus change interrupt will be enabled by its resume interface by mistake, and then continuous interrupt will be generated because usb otg is in host mode, it can't clear the vbus change status. The system have a protect mechanism that when one IRQ's handler return IRQ_NONE more than 99000 times, it will through a exception to inform such situation. That's the reason why system crash. Signed-off-by: Tony LIU --- drivers/usb/gadget/arcotg_udc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/arcotg_udc.c b/drivers/usb/gadget/arcotg_udc.c index ea81802a3ca6..842c54eb790f 100755 --- a/drivers/usb/gadget/arcotg_udc.c +++ b/drivers/usb/gadget/arcotg_udc.c @@ -3432,7 +3432,6 @@ static int fsl_udc_resume(struct platform_device *pdev) /* if in host mode, we need to do nothing */ if ((fsl_readl(&dr_regs->otgsc) & OTGSC_STS_USB_ID) == 0) { dr_phy_low_power_mode(udc_controller, true); - dr_wake_up_enable(udc_controller, true); goto end; } dr_controller_setup(udc_controller); @@ -3452,7 +3451,8 @@ end: * subsystem will not leave from low power mode. */ if (!udc_can_wakeup_system() && - (pdata->pmflags == 0)) { + (pdata->pmflags == 0) && + (fsl_readl(&dr_regs->otgsc) & OTGSC_STS_USB_ID)) { dr_wake_up_enable(udc_controller, true); } -- 2.39.5