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>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index e3fe5fd795f0..03de169ab365 100644
--- 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;