usb: host: xhci: use ffs() in xhci_mem_init()

The for loop to find page size bit can be replaced with ffs().

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220303110903.1662404-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 48114a4629088cd55cdc7a1143597983c6b78e0d..938eb2b907ab668a597687a09e1fcba9c015429c 100644 (file)
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2391,11 +2391,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
        page_size = readl(&xhci->op_regs->page_size);
        xhci_dbg_trace(xhci, trace_xhci_dbg_init,
                        "Supported page size register = 0x%x", page_size);
-       for (i = 0; i < 16; i++) {
-               if ((0x1 & page_size) != 0)
-                       break;
-               page_size = page_size >> 1;
-       }
+       i = ffs(page_size);
        if (i < 16)
                xhci_dbg_trace(xhci, trace_xhci_dbg_init,
                        "Supported page size of %iK", (1 << (i+12)) / 1024);