From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Denk Date: Mon, 14 Apr 2003 15:41:50 +0200 Subject: [U-Boot-Users] "date reset" for MPC8xx In-Reply-To: Your message of "Mon, 14 Apr 2003 15:16:50 +0200." <3E9AB4C2.6020500@imc-berlin.de> Message-ID: <20030414134155.14FC2C58B9@atlas.denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Steven, in message <3E9AB4C2.6020500@imc-berlin.de> you wrote: > > I think would should realy reset the MPC8xx's internal RTC when > calling "date reset" or "rtc_reset" instead of "nothing to do". But on the MPC8xx's internal RTC there is no "reset" function, so it is IMHO appropriate to do nothing. > Please find and consider the attached patch. > > Background: > > I have seen it several times, that the MPC8xx's internal RTC contains > an invalid date, e.g. negative times (caused by no or low battery). There is no "invalid date" in the Unix notation of time_t. Negative times (i. e. dates < January 1, 1970,00:00:00 UTC, are valid, too. > That might result in dates before 1970-01-01 under Linux and that in > turn confuses timeouts. Oops? I am not aware of any part in U-Boot (or Linux) that uses the system time for timeouts! And I cannot understand why January 1, 1970 should be any better than January 1, 1960 or January 1, 1950 or any other arbitrarily chosen date. > I've seen that udhcpc (from busybox) hangs in such cases! FIx this, then. > For that reason u-boot should check for valid dates and do a > rtc_reset() if nessesary. No. The RTC reset funtion is only to be used for RTC chips where the hardware supports such a reset operation. If you need a valid system time, please use the "date" command to set a valid time. Patch rejected. Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de Any sufficiently advanced technology is indistinguishable from magic. - Arthur C. Clarke