usb: musb: only set test mode once
The MUSB test mode register can only be set once, otherwise the result
is undefined.
This prevents the debugfs testmode entry to set the register more than
once which causes test failure.
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
index 78a283e..04382ec 100644
--- a/drivers/usb/musb/musb_debugfs.c
+++ b/drivers/usb/musb/musb_debugfs.c
@@ -191,9 +191,16 @@
{
struct seq_file *s = file->private_data;
struct musb *musb = s->private;
- u8 test = 0;
+ u8 test;
char buf[18];
+ test = musb_readb(musb->mregs, MUSB_TESTMODE);
+ if (test) {
+ dev_err(musb->controller, "Error: test mode is already set. "
+ "Please do USB Bus Reset to start a new test.\n");
+ return count;
+ }
+
memset(buf, 0x00, sizeof(buf));
if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
