From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Babic Date: Sun, 06 May 2012 18:28:05 +0200 Subject: [U-Boot] [PATCH 3/4 V2] i.MX28: Add delay after CPU bypass is cleared In-Reply-To: <1336060041-8803-3-git-send-email-marex@denx.de> References: <1336060041-8803-1-git-send-email-marex@denx.de> <1336060041-8803-3-git-send-email-marex@denx.de> Message-ID: <4FA6A695.6060503@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 On 03/05/2012 17:47, Marek Vasut wrote: > This solves issues when larger amount of DRAM is used. Behave the > same in case of CPU bypass as we do in case of EMI bypass, wait > 15 ms. We need to wait until the clock domain stabilizes. > > Signed-off-by: Marek Vasut > Cc: Wolfgang Denk > Cc: Detlev Zundel > Cc: Stefano Babic > Cc: Fabio Estevam > --- > > V2: Change the description, this issue seemed to have been caused by not > waiting after frobbing with the CPU bypass, it was unrelated to memory, > but had a direct impact, causing trouble. This was yet another X-File > of the imx-bootlets, sigh. > > arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c b/arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c > index 0d13537..a9b1bb6 100644 > --- a/arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c > +++ b/arch/arm/cpu/arm926ejs/mx28/spl_mem_init.c > @@ -149,6 +149,8 @@ void mx28_mem_setup_cpu_and_hbus(void) > /* Disable CPU bypass */ > writel(CLKCTRL_CLKSEQ_BYPASS_CPU, > &clkctrl_regs->hw_clkctrl_clkseq_clr); > + > + early_delay(15000); Is there some influence (I assume that from your commit message) between size of the RAM and amount of time to wait ? Then yes, with boards with even more memory (this patch touches a common MX28 file) this delay is not enough. Should we correlate the delay maybe with PHYS_SDRAM_1_SIZE (maybe early_delay(15000 * (PHYS_SDRAM_1_SIZE / 512MB)) ? Best regards, Stefano Babic -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de =====================================================================