[PATCH 1/2] usb: core: Copy parameter string correctly and remove superfluous null check

[PATCH 1/2] usb: core: Copy parameter string correctly and remove superfluous null check

[Kai-Heng Feng]

strsep() slices string, so the string gets copied by
param_set_copystring() at the end of quirks_param_set() is not the
original value.
Fix that by calling param_set_copystring() earlier.

The null check for val is unnecessary, the caller of quirks_param_set()
does not pass null string.
Remove the superfluous null check. This is found by Smatch.

Fixes: 027bd6cafd9a ("usb: core: Add "quirks" parameter for usbcore")
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/usb/core/quirks.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 6fb8d5433268..29e5f32b38df 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -31,10 +31,15 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp)
 	u16 vid, pid;
 	u32 flags;
 	size_t i;
+	int err;
+
+	err = param_set_copystring(val, kp);
+	if (err)
+		return err;
 
 	mutex_lock(&quirk_mutex);
 
-	if (!val || !*val) {
+	if (!*val) {
 		quirk_count = 0;
 		kfree(quirk_list);
 		quirk_list = NULL;
@@ -133,7 +138,7 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp)
 unlock:
 	mutex_unlock(&quirk_mutex);
 
-	return param_set_copystring(val, kp);
+	return 0;
 }
 
 static const struct kernel_param_ops quirks_param_ops = {
-- 
2.15.1

[PATCH 2/2] usb: core: Add USB_QUIRK_DELAY_CTRL_MSG to usbcore quirks

[Kai-Heng Feng]

There's a new quirk, USB_QUIRK_DELAY_CTRL_MSG. Add it to usbcore quirks
for completeness.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 4 +++-
 drivers/usb/core/quirks.c                       | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 61ab660f7fdc..a0b4377cb8da 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4454,7 +4454,9 @@
 					calculation);
 				m = USB_QUIRK_DISCONNECT_SUSPEND (Device needs
 					to be disconnected before suspend to
-					prevent spurious wakeup)
+					prevent spurious wakeup);
+				n = USB_QUIRK_DELAY_CTRL_MSG (Device needs a
+					pause after every control message);
 			Example: quirks=0781:5580:bk,0a5c:5834:gij
 
 	usbhid.mousepoll=
diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 29e5f32b38df..920f48a49a87 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -124,6 +124,9 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp)
 			case 'm':
 				flags |= USB_QUIRK_DISCONNECT_SUSPEND;
 				break;
+			case 'n':
+				flags |= USB_QUIRK_DELAY_CTRL_MSG;
+				break;
 			/* Ignore unrecognized flag characters */
 			}
 		}
-- 
2.15.1