From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikita Kiryanov Date: Mon, 04 Aug 2014 15:49:29 +0300 Subject: [U-Boot] [PATCH 09/18] arm: mx6: ddr: do not write into reserved bit In-Reply-To: References: <1407051288-17324-1-git-send-email-nikita@compulab.co.il> <1407051288-17324-10-git-send-email-nikita@compulab.co.il> Message-ID: <53DF8159.6040305@compulab.co.il> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Tim, On 04/08/14 08:43, Tim Harvey wrote: > On Sun, Aug 3, 2014 at 12:34 AM, Nikita Kiryanov wrote: >> Bit 16 in mapsr register is in a reserved field. Don't write to it. >> >> Cc: Stefano Babic >> Cc: Tim Harvey >> Signed-off-by: Nikita Kiryanov >> --- >> arch/arm/cpu/armv7/mx6/ddr.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm/cpu/armv7/mx6/ddr.c b/arch/arm/cpu/armv7/mx6/ddr.c >> index af91314..70ce38f 100644 >> --- a/arch/arm/cpu/armv7/mx6/ddr.c >> +++ b/arch/arm/cpu/armv7/mx6/ddr.c >> @@ -466,7 +466,7 @@ void mx6_dram_cfg(const struct mx6_ddr_sysinfo *sysinfo, >> 1 << 6 | /* BOTH_CS_PD */ >> (tcksrx & 0x7) << 3 | >> (tcksre & 0x7); >> - mmdc0->mapsr = 0x00011006; /* ADOPT power down enabled */ >> + mmdc0->mapsr = 0x00001006; /* ADOPT power down enabled */ >> >> /* Step 11: Configure ZQ calibration: one-time and periodic 1ms */ >> val = 0xa1390003; >> -- >> 1.9.1 >> > > Nikita, > > This makes sense per the reference manual, but does not agree with the > i.Mx6DQSDL DDR3 Script Aid spreadsheet > (https://community.freescale.com/docs/DOC-94917). I'm curious if you > found any other explanation of this or anything else that makes you > feel the spreadsheet is in error (vs the RM's). Nothing specific, I just don't like to use undocumented features. It's probably benign, but still... > I've asked our Freescale FAE to clarify. Looking forward to that... Regards, Nikita Kiryanov