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Subject: Re: [PATCH v5] usb: Reduce 'set_address' command timeout with a new
 quirk
From:   Sergey Shtylyov <s.shtylyov@omp.ru>
To:     Hardik Gajjar <hgajjar@de.adit-jv.com>,
        <gregkh@linuxfoundation.org>, <stern@rowland.harvard.edu>,
        <mathias.nyman@intel.com>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <erosca@de.adit-jv.com>
References: <de2ed64a-363a-464c-95be-584ce1a7a4ad@rowland.harvard.edu>
 <20231025141316.117514-1-hgajjar@de.adit-jv.com>
 <41e22c23-07b3-5fd9-5fb1-935ab42fa83e@omp.ru>
Organization: Open Mobile Platform
Message-ID: <671fe78d-413c-4bfb-84a2-560c41864619@omp.ru>
Date:   Wed, 25 Oct 2023 19:16:01 +0300
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On 10/25/23 7:00 PM, Sergey Shtylyov wrote:

[...]
>    Sorry to be PITA but... (-:

   I just had to speak up after Alan's ACK. :-)

>> This patch introduces a new USB quirk, USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT,
>> which modifies the timeout value for the 'set_address' command. The
> 
>    This is called a request, not a command by the spec. And the USB spec
> names the requests in all uppercase, e.g. SET_ADDRESS...
> 
>> standard timeout for this command is 5000 ms, as recommended in the USB
>> 3.2 specification (section 9.2.6.1).
> 
>    This section in the USB specs 1.1/2.0/3.0 talks about _all_ requests.
> I don't have USB 3.2 but It believe it has the same wording.
> 
> [...]
> 
>> Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
[...]

>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
>> index e1b1b64a0723..0c610a853aef 100644
>> --- a/drivers/usb/host/xhci.c
>> +++ b/drivers/usb/host/xhci.c
>> @@ -3998,11 +3998,17 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
>>  }
>>  
>>  /*
> 
>    You seem to be converting the existing comment to a kernel-doc one
> but you miss changing from /* /** at the start and adding colons after

   From /* to /**, I meant to type...

> the param names below...

   This comment update also looks like a meterial for a separate patch...

>> - * Issue an Address Device command and optionally send a corresponding
>> - * SetAddress request to the device.
>> + * xhci_setup_device - issues an Address Device command to assign a unique
>> + *			USB bus address.
>> + * @hcd USB host controller data structure.
>> + * @udev USB dev structure representing the connected device.
>> + * @setup Enum specifying setup mode: address only or with context.
>> + * @timeout_ms Max wait time (ms) for the command operation to complete.
>> + *
>> + * Return: 0 if successful; otherwise, negative error code.
>>   */
>>  static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
>> -			     enum xhci_setup_dev setup)
>> +			     enum xhci_setup_dev setup, unsigned int timeout_ms)
> [...]

MBR, Sergey