Override the default VID/PID if custom values are supplied through the
idVendor and idProduct kernel module parameters.

Signed-off-by: Jef Driesen <jefdriesen@telenet.be>
---
 drivers/usb/gadget/serial.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/gadget/serial.c b/drivers/usb/gadget/serial.c
index f46a609..77b410e 100644
--- a/drivers/usb/gadget/serial.c
+++ b/drivers/usb/gadget/serial.c
@@ -271,6 +271,11 @@ static int __init init(void)
 	}
 	strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
 
+	if (idVendor)
+		device_desc.idVendor = idVendor;
+	if (idProduct)
+		device_desc.idProduct = idProduct;
+
 	return usb_composite_register(&gserial_driver);
 }
 module_init(init);
-- 
1.7.1

--

[ message continues ]

So this patch resolves the bug found in
1ab83238740ff1e1773d5c13ecac43c60cf4aec4 which showed up in .35-rc1,
right?

Robert, any objection to this as it was your patch that broke things?

thanks,

--

[ message continues ]

Yes, although I'm really sure it is the best way to fix the problem. The way I 
understand this code is that before that commit, the 
idVendor/idProduct/bcdDevice module parameters where set after the bind(). Thus 
whatever was set as the default there got replaced with the values of the module 
parameters. Exactly what I would consider the correct behavior. After the 
commit, they get set before bind(), where they are changed back to the hardcoded 
values, which I think is wrong. My patch sets them back to the right values, but 
maybe it makes more sense to not set the default values in the first place (if 
there are already values in place of course). But I didn't knew how to 
accomplish that.

There might be similar problems for the other gadget drivers as well. I haven't 
--

[ message continues ]

Hi,

I just revisited the patch I submitted and I can see that it needs 
fixing. The intention of the patch was to provide the idVendor & 
idProduct kernel module parameter overrides to the individual 
functions at 'bind()' time. Prior to the patch, the overrides were 
done after the bind, making it hard for individual functions to 
determine the correct value for idVendor (some functions may need 
to use that value, e.g. USB audio when it registers itself
as an ALSA device; it would want to use the same Vendor id).

The patch makes sure that that happens, however, right after the bind()
the patched values are lost due to the copying of the gadget specific
device descriptor. Here's the snippet from 2.6.34:

 999        usb_gadget_set_selfpowered(gadget);
1000

1001        /* interface and string IDs start at zero via kzalloc.
1002         * we force endpoints to start unassigned; few controller
1003         * drivers will zero ep->driver_data.
1004         */
1005        usb_ep_autoconfig_reset(cdev->gadget);
1006
1007        /* composite gadget needs to assign strings for whole device (like
1008         * serial number), register function drivers, potentially update
1009         * power state and consumption, etc
1010         */
1011        status = composite->bind(cdev);
1012        if (status < 0)
1013                goto fail;
1014
1015        cdev->desc = *composite->dev;
1016        cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
1017
1018        /* standardized runtime overrides for device ID data */
1019        if (idVendor)
1020                cdev->desc.idVendor = cpu_to_le16(idVendor);
1021        if (idProduct)
1022                cdev->desc.idProduct = cpu_to_le16(idProduct);
1023        if (bcdDevice)
1024                cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
1025

In line 1015, the composite device descriptor is copied to the cdev->desc
field. Then the values get patched.

My patch just moved lines 1018-1024, so that the functions ...
[ message continues ]

So, do you want me to revert your original patch and wait for you to
come up with a "better" solution?

That seems like the correct thing to do at the moment.

thanks,

greg k-h
--

[ message continues ]

If the original commit is reverted, the idVendor and idProduct module parameters 
can still be accessed through the global variables directly (like I did in my 
own pathc). Since access to those values appears to be the main goal of the 
patch, I think no functionality will be lost by reverting the commit.
--

[ message continues ]

Hi,

Yes, providing access to those module parameters was the original goal. I agree that my patch should be reverted and I'll try to come up with a method of accessing these values without violating the information hiding principles too much. I don't like accessing globals.



This e-mail message contains information which is confidential and may be privileged. It is intended for use by the addressee only. If you are not the intended addressee, we request that you notify the sender immediately and delete or destroy this e-mail message and any attachment(s), without copying, saving, forwarding, disclosing or using its contents in any other way. TomTom N.V., TomTom International BV or any other company belonging to the TomTom group of companies will not be liable for damage relating to the communication by e-mail of data, documents or any other information.
--

[ message continues ]

Do I have to take any action to make sure the original commit [1] gets reverted?

[1] 1ab83238740ff1e1773d5c13ecac43c60cf4aec4
--

[ message continues ]

It's now reverted.

thanks,

greg k-h
--

[ message continues ]