linux-kernel - Re: [PATCH] ARM: rockchip: restore dapswjdp after suspend

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: <555D3CB7.2000002@rock-chips.com>
Date:	Thu, 21 May 2015 10:02:31 +0800
From:	"Huang, Tao" <huangtao@...k-chips.com>
To:	Doug Anderson <dianders@...omium.org>
CC:	Heiko Stuebner <heiko@...ech.de>, linux@....linux.org.uk,
	linux-kernel@...r.kernel.org, linux-rockchip@...ts.infradead.org,
	Chris Zhong <zyw@...k-chips.com>,
	linux-arm-kernel@...ts.infradead.org,
	Tony Xie <tony.xie@...k-chips.com>
Subject: Re: [PATCH] ARM: rockchip: restore dapswjdp after suspend

Hi, Doug:

在 2015年05月21日 04:34, Doug Anderson 写道:
> In the commit (0ea001d ARM: rockchip: disable dapswjdp during suspend)
> we made the assumption that we didn't need to restore dapswjdp after
> suspend because "the MASKROM will enable it back".
> 
> It turns out that's not a safe assumption.  In some cases (pending
> interrupts) it's possible that the WFI might act as a no-op and the
> MaskROM will never run.


I don't think this can happen. It seems we set PMU_GLOBAL_INT_DISABLE
bit, which means in power off flow, the IRQ will not accepted until the
ARM is power off. Do you see the SGRF_CPU_CON0[0] is 0 after resume?

Anyway, restore the value is okay, which make the code more symmetrically



  Since we're changing the bit, we should
> restore it ourselves.
> 
> Signed-off-by: Doug Anderson <dianders@...omium.org>
> ---
>  arch/arm/mach-rockchip/pm.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm/mach-rockchip/pm.c b/arch/arm/mach-rockchip/pm.c
> index b0dcbe2..a7be465 100644
> --- a/arch/arm/mach-rockchip/pm.c
> +++ b/arch/arm/mach-rockchip/pm.c
> @@ -48,6 +48,7 @@ static struct regmap *sgrf_regmap;
>  
>  static u32 rk3288_pmu_pwr_mode_con;
>  static u32 rk3288_sgrf_soc_con0;
> +static u32 rk3288_sgrf_cpu_con0;
>  
>  static inline u32 rk3288_l2_config(void)
>  {
> @@ -70,6 +71,7 @@ static void rk3288_slp_mode_set(int level)
>  {
>  	u32 mode_set, mode_set1;
>  
> +	regmap_read(sgrf_regmap, RK3288_SGRF_CPU_CON0, &rk3288_sgrf_cpu_con0);
>  	regmap_read(sgrf_regmap, RK3288_SGRF_SOC_CON0, &rk3288_sgrf_soc_con0);
>  
>  	regmap_read(pmu_regmap, RK3288_PMU_PWRMODE_CON,
> @@ -129,6 +131,9 @@ static void rk3288_slp_mode_set(int level)
>  
>  static void rk3288_slp_mode_set_resume(void)
>  {
> +	regmap_write(sgrf_regmap, RK3288_SGRF_CPU_CON0,
> +		     rk3288_sgrf_cpu_con0 | SGRF_DAPDEVICEEN_WRITE);
> +
>  	regmap_write(pmu_regmap, RK3288_PMU_PWRMODE_CON,
>  		     rk3288_pmu_pwr_mode_con);
>  
> 

--
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/