sh: sh7786: modify usb setup timeout judgment bug.

This corrects a race with the PHY RST bit not being set properly if the
PLL status changes right before timeout. This resulted in it potentially
failing even if the device came up in time.

Special thanks to Mr. Juha Leppanen and Iwamatsu-san for reporting this
out and reviewing it.

Reported-by: Juha Leppanen <juha_motorsportcom@luukku.com>
Reviewed-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/kernel/cpu/sh4a/setup-sh7786.c b/arch/sh/kernel/cpu/sh4a/setup-sh7786.c
index 5a47e1c..90e8cff 100644 (file)
--- a/arch/sh/kernel/cpu/sh4a/setup-sh7786.c
+++ b/arch/sh/kernel/cpu/sh4a/setup-sh7786.c
@@ -143,14 +143,14 @@ static void __init sh7786_usb_setup(void)
         * Set the PHY and PLL enable bit
         */
        __raw_writel(PHY_ENB | PLL_ENB, USBPCTL1);
-       while (i-- &&
-              ((__raw_readl(USBST) & ACT_PLL_STATUS) != ACT_PLL_STATUS))
+       while (i--) {
+               if (ACT_PLL_STATUS == (__raw_readl(USBST) & ACT_PLL_STATUS)) {
+                       /* Set the PHY RST bit */
+                       __raw_writel(PHY_ENB | PLL_ENB | PHY_RST, USBPCTL1);
+                       printk(KERN_INFO "sh7786 usb setup done\n");
+                       break;
+               }
                cpu_relax();
-
-       if (i) {
-               /* Set the PHY RST bit */
-               __raw_writel(PHY_ENB | PLL_ENB | PHY_RST, USBPCTL1);
-               printk(KERN_INFO "sh7786 usb setup done\n");
        }
 }