[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20190722114839.GA10515@kroah.com>
Date: Mon, 22 Jul 2019 13:48:39 +0200
From: "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>
To: Pawel Laszczak <pawell@...ence.com>
Cc: Pavel Machek <pavel@....cz>,
"felipe.balbi@...ux.intel.com" <felipe.balbi@...ux.intel.com>,
"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
"rogerq@...com" <rogerq@...com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"jbergsagel@...com" <jbergsagel@...com>,
"nsekhar@...com" <nsekhar@...com>, "nm@...com" <nm@...com>,
Suresh Punnoose <sureshp@...ence.com>,
Jayshri Dajiram Pawar <jpawar@...ence.com>,
Rahul Kumar <kurahul@...ence.com>,
Anil Joy Varughese <aniljoy@...ence.com>
Subject: Re: [PATCH v10 0/6] Introduced new Cadence USBSS DRD Driver.
On Mon, Jul 22, 2019 at 09:58:42AM +0000, Pawel Laszczak wrote:
> Hi,
>
> >
> >> This patch introduce new Cadence USBSS DRD driver to linux kernel.
> >>
> >> The Cadence USBSS DRD Controller is a highly configurable IP Core which
> >> can be instantiated as Dual-Role Device (DRD), Peripheral Only and
> >> Host Only (XHCI)configurations.
> >
> >I see you are using debugfs to select between DRD, peripheral-onlyh and XHCI...
> >
> >Is that good idea?
>
> Yes driver allows selecting dr_mode by debugfs. Controller also support such functionality
> so I don't understand why would it not be a good idea.
>
> I personally use this for testing but it can be used to limit controller functionality without
> recompiling kernel.
debugfs is ONLY for debugging, never rely on it being enabled, or
mounted, on a system in order to have any normal operation happen.
So for testing, yes, this is fine. If this is going to be the normal
api/interface for how to control this driver, no, that is not acceptable
at all.
thanks,
greg k-h
Powered by blists - more mailing lists