From: Jason Cooper Subject: Re: [PATCH 2/2] ath9k: disable RNG by default Date: Wed, 10 Aug 2016 13:24:49 +0000 Message-ID: <20160810132449.GH2013@io.lakedaemon.net> References: <1470726147-30095-1-git-send-email-miaoqing@codeaurora.org> <1526134.1iUazSISyZ@positron.chronox.de> <4321952.1nMxxDi7Wz@positron.chronox.de> <1e8e88ad7de64c528f08c75ff9176ab8@aptaiexm02f.ap.qualcomm.com> <389c3c1fdde2447aacf31a8b4aadfc08@aptaiexm02f.ap.qualcomm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stephan Mueller , Herbert Xu , Matt Mackall , "miaoqing-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org" , "Valo, Kalle" , "linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , ath9k-devel , "linux-crypto-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "Sepehrdad, Pouyan" To: "Pan, Miaoqing" Return-path: Content-Disposition: inline In-Reply-To: <389c3c1fdde2447aacf31a8b4aadfc08-fhY3XlRGNI1pWAYlkNb9jaRtKmQZhJ7pQQ4Iyu8u01E@public.gmane.org> Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-crypto.vger.kernel.org Hi Miaoqing Pan, Stephen, *gentle reminder: others are reading which may not be directly included in the conversation. Including the archives. Please avoid top posting. :) On Wed, Aug 10, 2016 at 07:43:45AM +0000, Pan, Miaoqing wrote: > The problem with using the add_device_randomness is that we do not > know when to call that API, and we have to make our solution either > timer-based or interrupt based, which is not really the correct way of > implementing this feature. Exactly. I think we're dancing around the problem by discussing the quality of what the ath9k adc provides. The fact is, barring userspace expectations of /dev/hwrng, hw_random is the appropriate place for it. It's not a devicetree blob, mac address, or pci config space. Which are things we feed in once for the heck of it. This is a *continuous* source or questionable quality. I'm seriously considering putting this and timeriomem-rng into a subdirectory under hw_random/, maybe environ/. Anything in there gets quality=0 for default, and *doesn't* contribute to /dev/hwrng. Regardless which path we take, I think we should include 'adc' in the name. I've heard countless times about "Atheros cards come with an rng on board". :-/ thx, Jason. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html