On 2012/9/12 21:11, Alan Stern wrote:
On Wed, 12 Sep 2012, Fengguang Wu wrote:Hi Felipe, FYI, there are new smatch warnings show up in tree: git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git merge-result-for-greg head: 23953bde3e4d6aa8780dc054f6ad9882ac63f4f4 commit: e918fa161f510136fce45a524e934fe20e62c8b1 [66/99] Merge tag 'gadget-for-v3.7' into merge-result-for-greg drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null)) drivers/usb/core/hub.c:4733 store_port_power_control() info: why not propagate 'ret' from set_port_feature() instead of -5? drivers/usb/core/hub.c:4744 store_port_power_control() info: why not propagate 'ret' from clear_port_feature() instead of -5? vim +2654 drivers/usb/core/hub.c 2644 return ret; 2645 } 2646 2647 static int usb_get_hub_port_power_state(struct usb_device *hdev, int port1) 2648 { 2649 struct usb_hub *hub = hdev_to_hub(hdev); 2650 struct usb_port_status data; 2651 u16 portstatus; 2652 int ret; 26532654 ret = get_port_status(hub->hdev, port1, &data);2655 if (ret < 4) { 2656 dev_err(hub->intfdev, 2657 "%s failed (err = %d)\n", __func__, ret); 2658 if (ret >= 0) 2659 ret = -EIO; 2660 return ret; 2661 } else 2662 portstatus = le16_to_cpu(data.wPortStatus); 2663 return port_is_power_on(hub, portstatus); 2664 }This is a real problem. It looks like it really is necessary to call hub_port_status() here, not get_port_status(). Would you like to fix this?
Yeah. I'd like to fix it.
The reason for changing the return codes from clear_port_feature() and set_port_feature() is simple. The values they return are meant for internal use within the kernel, whereas the return code from store_port_power_control() will be passed back to userspace. Alan Stern
-- Best Regards Tianyu Lan linux kernel enabling team -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
