Re: [PATCH v3 1/4] Simplify usbnet_cdc_update_filter

I get a panic if I remove this patch, because intf comes NULL for
cdc_ncm devices. I'll send an updated patch that solves this issue while
still using usb_control_msg.

On 02/07/18 10:25, Oliver Neukum wrote:

On So, 2018-07-01 at 11:05 +0200, Miguel Rodríguez Pérez         wrote:

quoted

Remove some unneded varibles to make the code easier to read
and, replace the generic usb_control_msg function for the
more specific usbnet_write_cmd.

Signed-off-by: Miguel Rodríguez Pérez <redacted>

No,

sorry, but this is not good. The reason is a bit subtle.
Drivers need to reset the filters when handling post_reset()
[ and reset_resume() ] usbnet_write_cmd() falls back to
kmemdup() with GFP_KERNEL. Usbnet is a framework with class
drivers and some of the devices we drive have a storage
interface. Thence we are on the block error handling path here.

The simplest solution is to leave out this patch in the sequence.

	Regards
		Oliver


NACKED-BY: Oliver Neukum [off-list ref]

quoted

---
 drivers/net/usb/cdc_ether.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 178b956501a7..815ed0dc18fe 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c

@@ -77,9 +77,7 @@ static const u8 mbm_guid[16] = {
 
 static void usbnet_cdc_update_filter(struct usbnet *dev)
 {
-	struct cdc_state	*info = (void *) &dev->data;
-	struct usb_interface	*intf = info->control;
-	struct net_device	*net = dev->net;
+	struct net_device *net = dev->net;
 
 	u16 cdc_filter = USB_CDC_PACKET_TYPE_DIRECTED
 			| USB_CDC_PACKET_TYPE_BROADCAST;

@@ -93,16 +91,13 @@ static void usbnet_cdc_update_filter(struct usbnet *dev)
 	if (!netdev_mc_empty(net) || (net->flags & IFF_ALLMULTI))
 		cdc_filter |= USB_CDC_PACKET_TYPE_ALL_MULTICAST;
 
-	usb_control_msg(dev->udev,
-			usb_sndctrlpipe(dev->udev, 0),
+	usbnet_write_cmd(dev,
 			USB_CDC_SET_ETHERNET_PACKET_FILTER,
-			USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+			USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
 			cdc_filter,
-			intf->cur_altsetting->desc.bInterfaceNumber,
+			dev->intf->cur_altsetting->desc.bInterfaceNumber,
 			NULL,
-			0,
-			USB_CTRL_SET_TIMEOUT
-		);
+			0);
 }
 
 /* probes control interface, claims data interface, collects the bulk

-- 
Miguel Rodríguez Pérez
Laboratorio de Redes
EE Telecomunicación – Universidade de Vigo