powerpc/vas: Reduce polling interval for busy state

A VAS window is normally in "busy" state for only a short duration.
Reduce the time we wait for the window to go to "not-busy" state to
speed-up vas_win_close() a bit.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 95622a984b0586436080b3577299393f1f8c5460..1422cdd7d91798341e4747357231ac92f4fc1acb 100644 (file)
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1060,21 +1060,23 @@ int vas_paste_crb(struct vas_window *txwin, int offset, bool re)
 }
 EXPORT_SYMBOL_GPL(vas_paste_crb);
 
+/*
+ * Wait for the window to go to "not-busy" state. It should only take a
+ * short time to queue a CRB, so window should not be busy for too long.
+ * Trying 5ms intervals.
+ */
 static void poll_window_busy_state(struct vas_window *window)
 {
        int busy;
        u64 val;
 
 retry:
-       /*
-        * Poll Window Busy flag
-        */
        val = read_hvwc_reg(window, VREG(WIN_STATUS));
        busy = GET_FIELD(VAS_WIN_BUSY, val);
        if (busy) {
                val = 0;
                set_current_state(TASK_UNINTERRUPTIBLE);
-               schedule_timeout(HZ);
+               schedule_timeout(msecs_to_jiffies(5));
                goto retry;
        }
 }