From mboxrd@z Thu Jan 1 00:00:00 1970 To: "John W. Linville" Cc: linuxppc-embedded@lists.linuxppc.org Subject: Re: Linux 2.4.17 bug, mmap of /dev/mem From: Wolfgang Denk Mime-version: 1.0 Content-type: text/plain; charset=ISO-8859-1 In-reply-to: Your message of "Tue, 26 Feb 2002 09:43:58 EST." <3C7B9F2E.40BC7C46@lvl7.com> Date: Tue, 26 Feb 2002 16:18:05 +0100 Message-Id: <20020226151810.2095D109E3@denx.denx.de> Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: John, in message <3C7B9F2E.40BC7C46@lvl7.com> you wrote: > > I've asked our hardware guys to take a look at the settings for the UPM > we are using to control SDRAM. Do you think we are on the right track? > Can you provide any guidance? Please be aware that UPM settings alone are NOT sufficient for a correct initialization of most SDRAM chips. Check with the documentation for your SDRAM chips, and follow the initialization sequence TO THE LETTER. Pay special attention to minimum and maximum delays, required dummy accesses, etc. Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de A committee is a life form with six or more legs and no brain. -- Lazarus Long, "Time Enough For Love" ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/