From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from kvm5.telegraphics.com.au (kvm5.telegraphics.com.au [98.124.60.144]) by lists.ozlabs.org (Postfix) with ESMTP id 41Vz5z6bGDzF35L for ; Wed, 18 Jul 2018 23:49:27 +1000 (AEST) Date: Wed, 18 Jul 2018 23:49:20 +1000 (AEST) From: Finn Thain To: Arnd Bergmann cc: Geert Uytterhoeven , Paul Mackerras , Michael Ellerman , Joshua Thompson , Mathieu Malaterre , Benjamin Herrenschmidt , Greg Ungerer , linux-m68k , linuxppc-dev , Linux Kernel Mailing List , y2038 Mailman List , Meelis Roos , Andreas Schwab Subject: Re: [PATCH 2/3] [v2] m68k: mac: use time64_t in RTC handling In-Reply-To: Message-ID: References: <20180619140229.3615110-1-arnd@arndb.de> <20180619140229.3615110-2-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 18 Jul 2018, Arnd Bergmann wrote: > Hmm, apparently I forgot to update via_read_time(), that one > is indeed bogus and now inconsistent with the other functions. > > The change in via_write_time() seems at least consistent wtih what we do > elsewhere, and using __u32 makes this code more portable. (yes, I > realize that 64-bit powermac doesn't use the VIA RTC, but it feels > better to write code portably anyway). > As for portability, I think you just contradicted yourself. But I take your point about consistency. So I won't object to adopting __u32. > I'd suggest we do it like below to make it consistent with the > rest again, using the 1904..2040 range of dates and no warning > for invalid dates. > > If you agree, I'll send that as a proper patch. > Geert may instead wish to fixup or revert the patch he has committed already... > Arnd > > diff --git a/arch/m68k/mac/misc.c b/arch/m68k/mac/misc.c > index bf8df47a6d09..8335509969f1 100644 > --- a/arch/m68k/mac/misc.c > +++ b/arch/m68k/mac/misc.c > @@ -255,12 +255,13 @@ static void via_write_pram(int offset, __u8 data) > * is basically any machine with Mac II-style ADB. > */ > > -static long via_read_time(void) > +static time64_t via_read_time(void) > { > union { > __u8 cdata[4]; > - long idata; > + __u32 idata; > } result, last_result; > + time64_t ret; ret isn't used. > int count = 1; > > via_pram_command(0x81, &last_result.cdata[3]); > @@ -279,12 +280,8 @@ static long via_read_time(void) > via_pram_command(0x89, &result.cdata[1]); > via_pram_command(0x8D, &result.cdata[0]); > > - if (result.idata == last_result.idata) { > - if (result.idata < RTC_OFFSET) > - result.idata += 0x100000000ull; > - > - return result.idata - RTC_OFFSET; > - } > + if (result.idata == last_result.idata) > + return (time64_t(result.idata) - RTC_OFFSET); > Did you mean to write, return (time64_t)result.idata - RTC_OFFSET; ? --