In xhci_hub_control(), there are many port register readbacks in several branches of the *switch* statement which get duplicated right after that *switch* by reading back the port register once more -- which is done to flush the posted writes. Remove the redundant reads inside that *switch*. Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx> --- This patch is against the 'usb-next' branch of Greg KH's 'usb.git' repo. drivers/usb/host/xhci-hub.c | 8 -------- 1 file changed, 8 deletions(-) Index: usb/drivers/usb/host/xhci-hub.c =================================================================== --- usb.orig/drivers/usb/host/xhci-hub.c +++ usb/drivers/usb/host/xhci-hub.c @@ -1323,7 +1323,6 @@ int xhci_hub_control(struct usb_hcd *hcd msleep(10); /* wait device to enter */ spin_lock_irqsave(&xhci->lock, flags); - temp = readl(ports[wIndex]->addr); bus_state->suspended_ports |= 1 << wIndex; break; case USB_PORT_FEAT_LINK_STATE: @@ -1341,7 +1340,6 @@ int xhci_hub_control(struct usb_hcd *hcd PORT_OCC | PORT_RC | PORT_PLC | PORT_CEC; writel(temp | PORT_PE, ports[wIndex]->addr); - temp = readl(ports[wIndex]->addr); break; } @@ -1351,7 +1349,6 @@ int xhci_hub_control(struct usb_hcd *hcd hcd->self.busnum, wIndex + 1); xhci_set_link_state(xhci, ports[wIndex], link_state); - temp = readl(ports[wIndex]->addr); break; } @@ -1384,8 +1381,6 @@ int xhci_hub_control(struct usb_hcd *hcd hcd->self.busnum, wIndex + 1); xhci_set_link_state(xhci, ports[wIndex], link_state); - - temp = readl(ports[wIndex]->addr); break; } /* Port must be enabled */ @@ -1435,7 +1430,6 @@ int xhci_hub_control(struct usb_hcd *hcd xhci_dbg(xhci, "missing U0 port change event for port %d-%d\n", hcd->self.busnum, wIndex + 1); spin_lock_irqsave(&xhci->lock, flags); - temp = readl(ports[wIndex]->addr); break; } @@ -1460,7 +1454,6 @@ int xhci_hub_control(struct usb_hcd *hcd break; } spin_lock_irqsave(&xhci->lock, flags); - temp = readl(ports[wIndex]->addr); bus_state->suspended_ports |= 1 << wIndex; } break; @@ -1491,7 +1484,6 @@ int xhci_hub_control(struct usb_hcd *hcd case USB_PORT_FEAT_BH_PORT_RESET: temp |= PORT_WR; writel(temp, ports[wIndex]->addr); - temp = readl(ports[wIndex]->addr); break; case USB_PORT_FEAT_U1_TIMEOUT: if (hcd->speed < HCD_USB3)
