Commit 017e6726 authored by Andrey Smirnov's avatar Andrey Smirnov Committed by Greg Kroah-Hartman
Browse files

xhci: Convert xhci_handshake() to use readl_poll_timeout_atomic()

commit f7fac17ca925faa03fc5eb854c081a24075f8bad upstream.

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: default avatarAndrey Smirnov <>
Tested-by: default avatarRaul E Rangel <>
Reviewed-by: default avatarRaul E Rangel <>
Cc: <>
Signed-off-by: default avatarMathias Nyman <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent ec70e2c1
......@@ -21,6 +21,7 @@
#include <linux/pci.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/log2.h>
#include <linux/module.h>
......@@ -46,7 +47,6 @@ static unsigned int quirks;
module_param(quirks, uint, S_IRUGO);
MODULE_PARM_DESC(quirks, "Bit flags for quirks to be enabled as default");
/* 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
......@@ -63,18 +63,16 @@ MODULE_PARM_DESC(quirks, "Bit flags for quirks to be enabled as default");
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;
} 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;
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