From 4b7440cc72276d2f7b9e805d809e5a48ae48cf6e Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Fri, 20 Nov 2015 09:06:27 -0800 Subject: [PATCH] UPSTREAM: usb: dwc2: host: Add missing spinlock in dwc2_hcd_reset_func() The dwc2_hcd_reset_func() function is only ever called directly by a delayed work function. As such no locks are already held when the function is called. Doing a read-modify-write of CPU registers and setting fields in the main hsotg data structure is a bad idea without locks. Let's add locks. The bug was found by code inspection only. It turns out that the dwc2_hcd_reset_func() is only ever called today if the "host_support_fs_ls_low_power" parameter is enabled and no code in mainline enables that parameter. Thus no known issues in mainline are fixed by this patch, but it's still probably wise to fix the function. Change-Id: I14ff93f64f1fd405d4911d67c7d0b20e50be4f53 Signed-off-by: Douglas Anderson Signed-off-by: Felipe Balbi Signed-off-by: Huang, Tao (cherry picked from commit 4a065c7bdbec9536f7b899241b125b9c3b5ba97a) --- drivers/usb/dwc2/hcd.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index 8a1a12c331f3..8847c72e55f6 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -2358,13 +2358,19 @@ static void dwc2_hcd_reset_func(struct work_struct *work) { struct dwc2_hsotg *hsotg = container_of(work, struct dwc2_hsotg, reset_work.work); + unsigned long flags; u32 hprt0; dev_dbg(hsotg->dev, "USB RESET function called\n"); + + spin_lock_irqsave(&hsotg->lock, flags); + hprt0 = dwc2_read_hprt0(hsotg); hprt0 &= ~HPRT0_RST; dwc2_writel(hprt0, hsotg->regs + HPRT0); hsotg->flags.b.port_reset_change = 1; + + spin_unlock_irqrestore(&hsotg->lock, flags); } /* -- 2.34.1