[PATCH] drm/debugfs: accept trailing whitespace in "force" attribute

[Michael Tretter]

Using plain echo to set the "force" connector attribute fails with
-EINVAL, because echo appends a newline to the output.

Strip trailing whitespace in the input before checking the value to
accept "off\n" or "off  ".

Signed-off-by: Michael Tretter <m.tretter at pengutronix.de>
---
 drivers/gpu/drm/drm_debugfs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index c1807d5754b2..10dd89d3f28e 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -241,6 +241,7 @@ static ssize_t connector_write(struct file *file, const char __user *ubuf,
 	struct seq_file *m = file->private_data;
 	struct drm_connector *connector = m->private;
 	char buf[12];
+	int i;
 
 	if (len > sizeof(buf) - 1)
 		return -EINVAL;
@@ -250,6 +251,10 @@ static ssize_t connector_write(struct file *file, const char __user *ubuf,
 
 	buf[len] = '\0';
 
+	/* strip trailing whitespace */
+	for (i = len - 1; i > 0 && isspace(buf[i]); i--)
+		buf[i] = '\0';
+
 	if (!strcmp(buf, "on"))
 		connector->force = DRM_FORCE_ON;
 	else if (!strcmp(buf, "digital"))
-- 
2.11.0