linux-kernel - Re: [PATCH] usb: xhci: bInterval quirk for TI TUSB73x0

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 10 Mar 2017 18:04:27 +0200
From:   Roger Quadros <rogerq@...com>
To:     Sergei Shtylyov <sergei.shtylyov@...entembedded.com>,
        <mathias.nyman@...el.com>
CC:     <linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] usb: xhci: bInterval quirk for TI TUSB73x0

On 09/03/17 11:44, Sergei Shtylyov wrote:
> Hello!
> 
> On 3/9/2017 11:47 AM, Roger Quadros wrote:
> 
>> As per [1] issue #4,
>> "The periodic EP scheduler always tries to schedule the EPs
>> that have large intervals (interval equal to or greater than
>> 128 microframes) into different microframes. So it maintains
>> an internal counter and increments for each large interval
>> EP added. When the counter is greater than 128, the scheduler
>> rejects the new EP. So when the hub re-enumerated 128 times,
>> it trigged this condition."
> 
>    Triggered.

Should be "triggers" actually.
Will fix it. Thanks.

> 
>> This results in Bandwidth error when devices with periodic
>> endpoints (ISO/INT) having bInterval > 7 are plugged an
>> unplugged several times on a TUSB73x0 xhci host.
>>
>> Workaround this issue by limiting the bInterval to 7
>> (i.e. interval to 6) for High-speed or faster periodic endpoints.
>>
>> [1] - http://www.ti.com/lit/er/sllz076/sllz076.pdf
>>
>> Signed-off-by: Roger Quadros <rogerq@...com>
> [...]
> 
> MBR, Sergei
> 

-- 
cheers,
-roger