usb: s3c-hsotg: Fix maximum patcket size setting for EP0

MPS field of DOEPCTL0 is read only.

Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index e3fe5fd..03de169 100644 (file)
--- a/drivers/usb/gadget/s3c-hsotg.c
+++ b/drivers/usb/gadget/s3c-hsotg.c
@@ -1696,10 +1696,12 @@ static void s3c_hsotg_set_ep_maxpacket(struct s3c_hsotg *hsotg,
        reg |= mpsval;
        writel(reg, regs + S3C_DIEPCTL(ep));
 
-       reg = readl(regs + S3C_DOEPCTL(ep));
-       reg &= ~S3C_DxEPCTL_MPS_MASK;
-       reg |= mpsval;
-       writel(reg, regs + S3C_DOEPCTL(ep));
+       if (ep) {
+               reg = readl(regs + S3C_DOEPCTL(ep));
+               reg &= ~S3C_DxEPCTL_MPS_MASK;
+               reg |= mpsval;
+               writel(reg, regs + S3C_DOEPCTL(ep));
+       }
 
        return;