From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 21420B7CED for ; Fri, 26 Mar 2010 09:57:43 +1100 (EST) Subject: Re: Continual reading from the PowerPc time base register is not stable From: Benjamin Herrenschmidt To: Chris Friesen In-Reply-To: <4BABDD16.4080705@nortel.com> References: <43c137a81003241941p84cba56y3e02e40cb22623e2@mail.gmail.com> <1269505301.8599.238.camel@pasglop> <201003251105.10033.arnd@arndb.de> <43c137a81003250800n660195c5k42c8516068aeda8d@mail.gmail.com> <4BABDD16.4080705@nortel.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 26 Mar 2010 09:57:31 +1100 Message-ID: <1269557851.8599.258.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Csdncannon , Arnd Bergmann List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2010-03-25 at 16:00 -0600, Chris Friesen wrote: > Shouldn't "upper" be cast to 64-bit before shifting? Yup but that doesn't explain his results. I think Segher nailed it to a stuck bit tho, so I would blame defective HW or HW used outside of normal operating conditions (maybe the TB is sourced out of bounds ?) Cheers, Ben.