This is a note to let you know that I've just added the patch titled
xhci: Convert xhci_handshake() to use readl_poll_timeout_atomic()
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From f7fac17ca925faa03fc5eb854c081a24075f8bad Mon Sep 17 00:00:00 2001
From: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
Date: Wed, 22 May 2019 14:34:01 +0300
Subject: 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@xxxxxxxxx>
Tested-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>
Reviewed-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 048a675bbc52..20db378a6012 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;
}
/*
--
2.21.0
