From 205845ef70dd01094415bceafbc86a97eb1899a9 Mon Sep 17 00:00:00 2001 From: Bin Liu Date: Tue, 24 Mar 2015 15:09:25 -0500 Subject: [PATCH] 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 Signed-off-by: Felipe Balbi --- drivers/usb/musb/musb_debugfs.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c index 78a283e9ce40..04382ec31d3f 100644 --- a/drivers/usb/musb/musb_debugfs.c +++ b/drivers/usb/musb/musb_debugfs.c @@ -191,9 +191,16 @@ static ssize_t musb_test_mode_write(struct file *file, { 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))) -- 2.20.1