linux-kernel - Re: [RFC 11/19] dwc3: add OTG handling code

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]

Message-ID: <CABYS0917SRw0CRb0_82Q=OQfn9=xObVcoRWqAiQKOh-C8ci1-A@mail.gmail.com>
Date:	Thu, 19 Mar 2015 13:08:13 +0530
From:	George Cherian <gcherianv@...il.com>
To:	Robert Baldyga <r.baldyga@...sung.com>
Cc:	balbi@...com, gregkh@...uxfoundation.org, myungjoo.ham@...sung.com,
	cw00.choi@...sung.com, linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org, m.szyprowski@...sung.com
Subject: Re: [RFC 11/19] dwc3: add OTG handling code

Hi Robert,


On Wed, Mar 18, 2015 at 7:34 PM, Robert Baldyga <r.baldyga@...sung.com> wrote:
>
> This patch introduces OTG support in DWC3 driver. OTG feature is responsible
> for dynamic USB role switching (between host and peripheral modes) based
> on detected cable type.
>
> Each role switch causes complete core reinitialization. In peripheral

Do you really want to do complete core reinitialization?
While switching to HOST mode you might need to issue a LHRESET and
while switching
to Device mode make sure you re-initiallize the event buffer addresses.

If LHRESET is not used then you should do what you have done.

But I don't think adding and removing the platform_device for XHCI is
the way to go.
This might impact SoC's which really implement the OTG for DWC3.

I made an attempt on the same  and could'nt work on it more.
This still has some issues, but could be fixed.
https://lkml.org/lkml/2014/11/25/600

> mode UDC device is activated using VBUS session control mechanism. In
> host mode the new XHCI device is registered to make bus visible in system.
>
> This code is inspired by DWC3 driver from Hardkernel Linux sources [1].
>
> [1] https://github.com/hardkernel/linux.
>
> Signed-off-by: Robert Baldyga <r.baldyga@...sung.com>

Regards
-George
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/