Re: [PATCH 04/10] USB: core: hub.c: use usb_control_msg_send() in a few places

2 Sep 2020


      On Wed, Sep 02, 2020 at 01:01:06PM +0200, Greg Kroah-Hartman wrote:
...
There are a few calls to usb_control_msg() that can be converted to use
usb_control_msg_send() instead, so do that in order to make the error
checking a bit simpler and the code smaller.
Cc: Alan Stern stern@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
One problem in this patch...
...
@@ -3896,27 +3875,14 @@ static int usb_req_set_sel(struct usb_device *udev, enum usb3_link_state state)
   if (u2_pel > USB3_LPM_MAX_U2_SEL_PEL)
   	u2_pel = USB3_LPM_MAX_U2_SEL_PEL;

/*
* usb_enable_lpm() can be called as part of a failed device reset,


* which may be initiated by an error path of a mass storage driver.


* Therefore, use GFP_NOIO.


*/


sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO);
if (!sel_values)
return -ENOMEM;



sel_values->u1_sel = u1_sel;
sel_values->u1_pel = u1_pel;
sel_values->u2_sel = cpu_to_le16(u2_sel);
sel_values->u2_pel = cpu_to_le16(u2_pel);


sel_values.u1_sel = u1_sel;
sel_values.u1_pel = u1_pel;
sel_values.u2_sel = cpu_to_le16(u2_sel);
sel_values.u2_pel = cpu_to_le16(u2_pel);


ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	USB_REQ_SET_SEL,


	USB_RECIP_DEVICE,


	0, 0,


	sel_values, sizeof *(sel_values),


	USB_CTRL_SET_TIMEOUT);


kfree(sel_values);


ret = usb_control_msg_send(udev, 0, USB_REQ_SET_SEL, USB_RECIP_DEVICE,
		   0, 0, &sel_values, sizeof(sel_values),


		   USB_CTRL_SET_TIMEOUT);



This effectively changes GFP_NOIO to GFP_KERNEL.  Probably you should
leave this particular call alone.
Alan Stern

    