xhci: Convert xhci_handshake() to use readl_poll_timeout_atomic() (f7fac17c) · Commits · 戴 / test

Xhci_handshake() implements the algorithm already captured by readl_poll_timeout_atomic(). Convert the former to use the latter to avoid repetition. Turned out this patch also fixes a bug on the AMD Stoneyridge platform where usleep(1) sometimes takes over 10ms. This means a 5 second timeout can easily take over 15 seconds which will trigger the watchdog and reboot the system. [Add info about patch fixing a bug to commit message -Mathias] Signed-off-by:

Andrey Smirnov <andrew.smirnov@gmail.com> Tested-by:

Raul E Rangel <rrangel@chromium.org> Reviewed-by:

Raul E Rangel <rrangel@chromium.org> Cc: <stable@vger.kernel.org> Signed-off-by:

Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci.c

+10 −12

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@
		*/

		#include <linux/pci.h>
		#include <linux/iopoll.h>
		#include <linux/irq.h>
		#include <linux/log2.h>
		#include <linux/module.h>
		@@ -52,7 +53,6 @@ static bool td_on_ring(struct xhci_td td, struct xhci_ring ring)
		return false;
		}

		/* TODO: copied from ehci-hcd.c - can this be refactored? */
		/*
		* xhci_handshake - spin reading hc until handshake completes or fails
		* @ptr: address of hc register to be read
		@@ -69,18 +69,16 @@ static bool td_on_ring(struct xhci_td td, struct xhci_ring ring)
		int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, int usec)
		{
		u32 result;
		int ret;

		do {
		result = readl(ptr);
		if (result == ~(u32)0) /* card removed */
		ret = readl_poll_timeout_atomic(ptr, result,
		(result & mask) == done \|\|
		result == U32_MAX,
		1, usec);
		if (result == U32_MAX) /* card removed */
		return -ENODEV;
		result &= mask;
		if (result == done)
		return 0;
		udelay(1);
		usec--;
		} while (usec > 0);
		return -ETIMEDOUT;

		return ret;
		}

		/*

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