From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Schmidt Subject: Re: [Alsa-devel] Re: irq handler top half timestamps Date: Fri, 10 Dec 2004 18:23:59 +0100 Message-ID: <20041210182359.2a5dc4a4@mango.fruits.de> References: <20041209180706.GA11397@elte.hu> <200412091819.iB9IJiLX013123@localhost.localdomain> <20041209183342.GB13132@elte.hu> <20041209220741.7562b6a0@mango.fruits.de> <1102626628.21688.11.camel@krustophenia.net> <20041210023548.5042f406@mango.fruits.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: jackit-devel-admin@lists.sourceforge.net Errors-To: jackit-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Jaroslav Kysela Cc: Lee Revell , Ingo Molnar , Paul Davis , jackit-devel@lists.sourceforge.net, alsa-devel List-Id: alsa-devel@alsa-project.org On Fri, 10 Dec 2004 08:52:39 +0100 (CET) Jaroslav Kysela wrote: > On Fri, 10 Dec 2004, Florian Schmidt wrote: > > > So it would be very useful, if, for example, the top half irq handler of > > the alsa driver would timestamp each IRQ with i.e. a TSC timestamp and > > expose this timestamp to the application in userspace. > > We can do any timestamp in the IRQ handler (this enum can be extended): > > enum sndrv_pcm_tstamp { > SNDRV_PCM_TSTAMP_NONE = 0, > SNDRV_PCM_TSTAMP_MMAP, > SNDRV_PCM_TSTAMP_LAST = SNDRV_PCM_TSTAMP_MMAP, > }; > > And this structure is used to store timestamp value: > > struct timespec tstamp; Way cool! But how to access it from userspace? Flo -- Palimm Palimm! http://affenbande.org/~tapas/ ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/