Mathias,
Are there any plans to backport this to the other kernels?
Looks like it landed upstream as f7fac17ca925faa03fc5eb854c081a24075f8bad
Thanks,
Raul
On Wed, May 22, 2019 at 02:27:29PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>
> 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
>
>
