| Message ID | 20190207000308.7051-1-andrew.smirnov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xhci: Convert xhci_handshake() to use readl_poll_timeout() | expand |
On 07.02.2019 02:03, Andrey Smirnov wrote: > Xhci_handshake() implements the algorithm already captured by > readl_poll_timeout(). Convert the former to use the latter to avoid > repetition. readl_poll_timeout() doesn't really work here as it might sleep. iopoll.h: /** * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs * ... * Returns 0 on success and -ETIMEDOUT upon a timeout. In either * case, the last read value at @addr is stored in @val. Must not * be called from atomic context if sleep_us or timeout_us are used. -Mathias
Hi, Mathias Nyman <mathias.nyman@linux.intel.com> writes: > On 07.02.2019 02:03, Andrey Smirnov wrote: >> Xhci_handshake() implements the algorithm already captured by >> readl_poll_timeout(). Convert the former to use the latter to avoid >> repetition. > > readl_poll_timeout() doesn't really work here as it might sleep. > > iopoll.h: > > /** > * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs > * > ... > * Returns 0 on success and -ETIMEDOUT upon a timeout. In either > * case, the last read value at @addr is stored in @val. Must not > * be called from atomic context if sleep_us or timeout_us are used. readl_poll_timeout_atomic()?
On Thu, Feb 7, 2019 at 12:27 AM Mathias Nyman <mathias.nyman@linux.intel.com> wrote: > > On 07.02.2019 02:03, Andrey Smirnov wrote: > > Xhci_handshake() implements the algorithm already captured by > > readl_poll_timeout(). Convert the former to use the latter to avoid > > repetition. > > readl_poll_timeout() doesn't really work here as it might sleep. > > iopoll.h: > > /** > * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs > * > ... > * Returns 0 on success and -ETIMEDOUT upon a timeout. In either > * case, the last read value at @addr is stored in @val. Must not > * be called from atomic context if sleep_us or timeout_us are used. > > -Mathias Shoot, missed this part. Will change to readl_poll_timeout_atomic() in v2. Thanks, Andrey Smirnov
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 005e65922608..1b5306001340 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(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(). 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 --- drivers/usb/host/xhci.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-)