From: Andrey Smirnov andrew.smirnov@gmail.com

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 --- drivers/usb/host/xhci.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 048a675..20db378 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -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 */ - return -ENODEV; - result &= mask; - if (result == done) - return 0; - udelay(1); - usec--; - } while (usec > 0); - return -ETIMEDOUT; + ret = readl_poll_timeout_atomic(ptr, result, + (result & mask) == done || + result == U32_MAX, + 1, usec); + if (result == U32_MAX) /* card removed */ + return -ENODEV; + + return ret; }

/*