2012/3/19 Sergei Shtylyov <sshtylyov@xxxxxxxxxx>:
> Hello.
>
> On 19-03-2012 10:55, Elric Fu wrote:
>
> Some grammar nitpicking...
>
>
>> When the Seagate Goflex USB3.0 device is attached to VIA xHCI
>> host, sometimes the device will down mode to high speed.
>
>
> s/down/downgrade/?
Yes, you are right. I made a mistake.
>
>> By
>
> s/By/With the help of/
>
why?I don't think it is a grammar error.
>
>> the USB analyzer, I found the device finished the link training
>> process and worked at superspeed mode. But the device descriptor
>> got from the device shows the device works at 2.1. It is very
>> strange and seems like the device controller of Seagate Goflex
>> has a little confusion.
>
>
>> The first 8 bytes of device descriptor should be:
>> 12 01 00 03 00 00 00 09
>
>
>> But the first 8 bytes of wrong device descriptor are:
>> 12 01 10 02 00 00 00 40
>
>
>> The wrong device descriptor caused the initialization of mass
>> storage failed. After a while, the device would be recognized
>> as a high speed device and works fine.
>
>
>> This patch will warm reset the device to fix the issue after
>> finding the bcdUSB field of device descriptor isn't 0x0300
>> but the speed mode of device is superspeed.
>
>
>> Signed-off-by: Elric Fu<elricfu1@xxxxxxxxx>
>> ---
>> drivers/usb/core/hub.c | 16 ++++++++++++++++
>> 1 files changed, 16 insertions(+), 0 deletions(-)
>
>
>> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
>> index 265c2f6..5e4f3e0 100644
>> --- a/drivers/usb/core/hub.c
>> +++ b/drivers/usb/core/hub.c
>> @@ -3071,6 +3071,22 @@ hub_port_init (struct usb_hub *hub, struct
>> usb_device *udev, int port1,
>> if (retval)
>> goto fail;
>>
>> + /*
>> + * Some superspeed devices have finished the link training process
>> + * and attached to a superspeed hub port, but the device
>> descriptor
>> + * got from those devices show they aren't superspeed devices.
>> Warm
>> + * reset the port attached by the devices can fix them.
>> + */
>> + if ((udev->speed == USB_SPEED_SUPER) &&
>> + (udev->descriptor.bcdUSB != 0x0300)) {
>
>
> () around == and != are not necessary.
>
No, I think it is necessary. It makes the code more clear. I hate that kind
of coding style.
>
>> + dev_err(&udev->dev, "get a wrong device descriptor, "
>
>
> s/get/got/
Yes, it is a grammar error.I will modify it.
>
> WBR, Sergei
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