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xhci: Convert xhci_handshake() to use readl_poll_timeout_atomic() 

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>
hifive-unleashed-5.2
Andrey Smirnov 2019-05-22 14:34:01 +03:00 committed by Greg Kroah-Hartman
parent 13b82b7463
commit f7fac17ca9
1 changed files with 10 additions and 12 deletions
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22
drivers/usb/host/xhci.c
View File

@ -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;
}
/*