[PATCH net-next v3 0/2] ch9200: stop ignoring the register write errors

[PATCH net-next v3 0/2] ch9200: stop ignoring the register write errors

[Sergey Shtylyov]

The successful register writes, done via the USB control requests, seem
vital for the normal functioning of the device, however the driver tends
to completely ignore the register write errors, even though it could well
propagate the errors from its bind() method.  Additionally, it masks any
USB errors returned by usb_control_msg(), pretending that the call was
successful. Let's stop doing all that and see how it goes... :-)

Sergey Shtylyov (2):
  ch9200: return error on failed register writes in ch9200_bind()
  ch9200: do return USB errors from control_write()

 drivers/net/usb/ch9200.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

-- 
2.55.0

[PATCH net-next v3 1/2] ch9200: return error on failed register writes in ch9200_bind()

[Sergey Shtylyov]

The successful register writes, done via the USB control requests in
control_write(), seem vital for the normal functioning of the device,
however the driver's bind() method ignores error codes returned from
control_write().  Do bail out of ch9200_bind() on failed writes...

Found by Linux Verification Center (linuxtesting.org) with the Svace
static analysis tool.

Signed-off-by: Sergey Shtylyov <s.shtylyov@auroraos.dev>

---
Changes in version 3:
- dropped the Fixes tag, retargeting the patch to the net-next.git repo again.

Changes in version 2:
- switched to checking for the negative error values instead of non-zero;
- added the Fixes tag, retargeting the patch to the net.git repo;
- dropped [RFT] from the subject.

 drivers/net/usb/ch9200.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/net/usb/ch9200.c b/drivers/net/usb/ch9200.c
index a206ffa76f1b..ab3cd3902ed7 100644
--- a/drivers/net/usb/ch9200.c
+++ b/drivers/net/usb/ch9200.c
@@ -360,32 +360,44 @@ static int ch9200_bind(struct usbnet *dev, struct usb_interface *intf)
 	data[1] = 0x0F;
 	retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_THRESHOLD, data,
 			       0x02, CONTROL_TIMEOUT_MS);
+	if (retval < 0)
+		return retval;
 
 	data[0] = 0xA0;
 	data[1] = 0x90;
 	retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_FIFO_DEPTH, data,
 			       0x02, CONTROL_TIMEOUT_MS);
+	if (retval < 0)
+		return retval;
 
 	data[0] = 0x30;
 	data[1] = 0x00;
 	retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_PAUSE, data,
 			       0x02, CONTROL_TIMEOUT_MS);
+	if (retval < 0)
+		return retval;
 
 	data[0] = 0x17;
 	data[1] = 0xD8;
 	retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_FLOW_CONTROL,
 			       data, 0x02, CONTROL_TIMEOUT_MS);
+	if (retval < 0)
+		return retval;
 
 	/* Undocumented register */
 	data[0] = 0x01;
 	data[1] = 0x00;
 	retval = control_write(dev, REQUEST_WRITE, 0, 254, data, 0x02,
 			       CONTROL_TIMEOUT_MS);
+	if (retval < 0)
+		return retval;
 
 	data[0] = 0x5F;
 	data[1] = 0x0D;
 	retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_CTRL, data, 0x02,
 			       CONTROL_TIMEOUT_MS);
+	if (retval < 0)
+		return retval;
 
 	retval = get_mac_address(dev, addr);
 	eth_hw_addr_set(dev->net, addr);
-- 
2.55.0

[PATCH net-next v3 2/2] ch9200: do return USB errors from control_write()

[Sergey Shtylyov]

Compared with control_read(), control_write() looks really strange:
it ignores any errors returned by usb_control_msg(), always returning
0 instead, despite overriding a positive result of usb_control_msg()
(indicating short transfer) to -EINVAL before doing that. Drop that
dubious *return* and propagate USB errors to the callers...

Signed-off-by: Sergey Shtylyov <s.shtylyov@auroraos.dev>

---
Changes in version 2:
- dropped the Fixes tag, retargeting the patch to the net-next.git repo;
- dropped [RFT] from the subject.

 drivers/net/usb/ch9200.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/usb/ch9200.c b/drivers/net/usb/ch9200.c
index ab3cd3902ed7..5cd825f26420 100644
--- a/drivers/net/usb/ch9200.c
+++ b/drivers/net/usb/ch9200.c
@@ -168,8 +168,6 @@ static int control_write(struct usbnet *dev, unsigned char request,
 		err = -EINVAL;
 	kfree(buf);
 
-	return 0;
-
 err_out:
 	return err;
 }
-- 
2.55.0