linux-kernel - Re: [PATCH 2a/5] Remove unsafe clock values from omap1

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <201112012023.04635.jkrzyszt@tis.icnet.pl>
Date:	Thu, 1 Dec 2011 20:23:04 +0100
From:	Janusz Krzysztofik <jkrzyszt@....icnet.pl>
To:	Tony Lindgren <tony@...mide.com>
Cc:	Paul Walmsley <paul@...an.com>, linux-omap@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2a/5] Remove unsafe clock values from omap1_defconfig

On Thursday 01 of December 2011 at 20:04:55, Tony Lindgren wrote:
> 
> From: Tony Lindgren <tony@...mide.com>
> Date: Thu, 1 Dec 2011 11:00:11 -0800
> Subject: [PATCH] ARM: OMAP1: Fix reprogramming of DPLL1 for systems that boot at rates below 60MHz
> 
> Commit e9b7086b80c4d9e354f4edc9e280ae85a60df408 (ARM: OMAP: Fix
> reprogramming of dpll1 rate) fixed a regression for systems that
> did not rely on bootloader set rates.
> 
> However, it also introduced a new problem where the rates selected
> in .config would not take affect as omap1_select_table_rate
> currently refuses to reprogram DPLL1 if it's already initialized.
> 
> This was not a problem earlier, as the reprogramming was done
> earlier with ck_dpll1_p->rate uninitialized.
> 
> Fix this by forcing the reprogramming on systems booting at rates
> below 60MHz. Note that the long term fix is to make the rates
> SoC specific later on.
> 
> Thanks for Janusz Krzysztofik <jkrzyszt@....icnet.pl> for figuring
> this one out.
> 
> Reported-by: Janusz Krzysztofik <jkrzyszt@....icnet.pl>
> Signed-off-by: Tony Lindgren <tony@...mide.com>

Acked-by: Janusz Krzysztofik <jkrzyszt@....icnet.pl>

However, this way or another, we are back to your mentioned problem of 
omap1_defconfig always switching to 216 MHz, I'm afraid. Then, 2a/5 v1 
"Remove unsafe clock values from omap1_defconfig" can still be helpful.

Anyway, I'm resending (refreshed) 2/5 and 5/5 as rc fixes as you 
suggested before, 1/5 "ARM: OMAP1: Fix dpll1 default rate reprogramming 
method" intended for next, and 2a/5 v2 "ARM: OMAP1: select clock rate by 
CPU type" also for next but as an RFC. 

Thanks,
Janusz

> 
> diff --git a/arch/arm/mach-omap1/clock_data.c b/arch/arm/mach-omap1/clock_data.c
> index 1297bb5..3f30561 100644
> --- a/arch/arm/mach-omap1/clock_data.c
> +++ b/arch/arm/mach-omap1/clock_data.c
> @@ -930,6 +930,9 @@ void __init omap1_clk_late_init(void)
>  	if (ck_dpll1.rate >= OMAP1_DPLL1_SANE_VALUE)
>  		return;
>  
> +	/* System booting at unusable rate, force reprogramming of DPLL1 */
> +	ck_dpll1_p->rate = 0;
> +
>  	/* Find the highest supported frequency and enable it */
>  	if (omap1_select_table_rate(&virtual_ck_mpu, ~0)) {
>  		pr_err("System frequencies not set, using default. Check your config.\n");
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/