From: Lu Baolu Date: Fri, 7 Apr 2017 14:56:50 +0000 (+0300) Subject: usb: xhci: clear EINT bit in status correctly X-Git-Tag: v4.12-rc1~97^2~50 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d1001ab41064c7fe7bffbc1d7c3921912f3ec32d;p=karo-tx-linux.git usb: xhci: clear EINT bit in status correctly EINT(Event Interrupt) is a write-1-to-clear type of bit in xhci status register. It should be cleared by writing a 1. Writing 0 to this bit has no effect. Xhci driver tries to clear this bit by writing 0 to it. This is not the right way to go. This patch corrects this by reading the register first, then clearing all RO/RW1C/RsvZ bits and setting the clearing bit, and writing back the new value at last. Xhci spec requires that software that uses EINT shall clear it prior to clearing any IP flags in section 5.4.2. This is the reason why this patch is CC'ed stable as well. [old way didn't cause any issues, skip stable, send to next -Mathias] Cc: Felipe Balbi Signed-off-by: Lu Baolu Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 643e31d08bb2..e3c785638332 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -724,7 +724,7 @@ void xhci_stop(struct usb_hcd *hcd) xhci_dbg_trace(xhci, trace_xhci_dbg_init, "// Disabling event ring interrupts"); temp = readl(&xhci->op_regs->status); - writel(temp & ~STS_EINT, &xhci->op_regs->status); + writel((temp & ~0x1fff) | STS_EINT, &xhci->op_regs->status); temp = readl(&xhci->ir_set->irq_pending); writel(ER_IRQ_DISABLE(temp), &xhci->ir_set->irq_pending); xhci_print_ir_set(xhci, 0); @@ -1057,7 +1057,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) xhci_dbg(xhci, "// Disabling event ring interrupts\n"); temp = readl(&xhci->op_regs->status); - writel(temp & ~STS_EINT, &xhci->op_regs->status); + writel((temp & ~0x1fff) | STS_EINT, &xhci->op_regs->status); temp = readl(&xhci->ir_set->irq_pending); writel(ER_IRQ_DISABLE(temp), &xhci->ir_set->irq_pending); xhci_print_ir_set(xhci, 0);