| Message ID | 20190208014816.21869-1-andrew.smirnov@gmail.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | f7fac17ca925faa03fc5eb854c081a24075f8bad |
| Headers | show |
| Series | [v2] xhci: Convert xhci_handshake() to use readl_poll_timeout_atomic() | expand |
On Thu, Feb 07, 2019 at 05:48:16PM -0800, Andrey Smirnov wrote: > Xhci_handshake() implements the algorithm already captured by > readl_poll_timeout_atomic(). Convert the former to use the latter to > avoid repetition. > > 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> This fixes a bug on the AMD Stoneyridge platform. 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. Thanks for the patch.
On 29.4.2019 23.05, Raul Rangel wrote: > On Thu, Feb 07, 2019 at 05:48:16PM -0800, Andrey Smirnov wrote: >> Xhci_handshake() implements the algorithm already captured by >> readl_poll_timeout_atomic(). Convert the former to use the latter to >> avoid repetition. >> >> 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> > > This fixes a bug on the AMD Stoneyridge platform. 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. > > Thanks for the patch. Adding to queue -Mathias
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 005e65922608..51c25a664ca4 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; } /*
Xhci_handshake() implements the algorithm already captured by readl_poll_timeout_atomic(). Convert the former to use the latter to avoid repetition. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-usb@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- Changes since [v1]: - Replaced readl_poll_timeout() with readl_poll_timeout_atomic() [v1] https://lore.kernel.org/lkml/20190207000308.7051-1-andrew.smirnov@gmail.com drivers/usb/host/xhci.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-)