From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/8] ARM: tegra: add common resume handling code for LP1 resuming
Date: Mon, 29 Jul 2013 16:38:59 -0600 [thread overview]
Message-ID: <51F6EF03.9000003@wwwdotorg.org> (raw)
In-Reply-To: <1374830110-30685-2-git-send-email-josephl@nvidia.com>
On 07/26/2013 03:15 AM, Joseph Lo wrote:
> The common LP1 resuming procedures of LP1 on Tegra was checking the LP1
> mask first. The LP1 mask indicated that the Tegra device was in LP1 then
> we need to resume the Tegra from the LP1 reset handler.
>
> And the LP1 was putting the SDRAM to self-refresh mode, the SDRAM wasn't
> accessible when resuming from LP1. We need to copy the LP1 reset handler
> to IRAM before suspending. That's why you can see the address of LP1
> reset handler was located in IRAM.
That's rather hard to understand. How about:
==========
Add support to the Tegra CPU reset vector to detect whether the CPU is
resuming from LP1 suspend state. If it is, branch to the LP1-specific
resume code.
When Tegra enters the LP1 suspend state, the SDRAM controller is placed
into a self-refresh state. For this reason, we must place the LP1 resume
code into IRAM, so that it is accessible before SDRAM access has been
re-enabled.
==========
Talking about *copying* the LP1 resume code to IRAM isn't appropriate
here, since nothing in this patch performs any copying of the resume code.
> diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
> @@ -182,6 +182,19 @@ after_errata:
> 1:
> #endif
>
> + /* Waking up from LP1? */
> + ldr r8, [r12, #RESET_DATA(MASK_LP1)]
> + tst r8, r11 @ if in_lp1
> + beq __is_not_lp1
> + cmp r10, #0
> + bne __die @ only CPU0 can be here
> + ldr lr, [r12, #RESET_DATA(STARTUP_LP1)]
> + THUMB( add lr, lr, #1 ) @ switch to Thumb mode
> + cmp lr, #0
> + bleq __die @ no LP1 startup handler
On thumb, lr==#1 at this point. I think you want to move the THUMB()
instruction after the bleq.
> diff --git a/arch/arm/mach-tegra/sleep.h b/arch/arm/mach-tegra/sleep.h
> +#define TEGRA_IRAM_CODE_AREA (TEGRA_IRAM_BASE + SZ_4K)
The layout of IRAM should be described in irammap.h not sleep.h.
next prev parent reply other threads:[~2013-07-29 22:38 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-26 9:15 [PATCH 0/8] ARM: tegra: support LP1 suspend mode Joseph Lo
2013-07-26 9:15 ` [PATCH 1/8] ARM: tegra: add common resume handling code for LP1 resuming Joseph Lo
2013-07-29 22:38 ` Stephen Warren [this message]
2013-07-26 9:15 ` [PATCH 2/8] ARM: tegra: config the polarity of the request of sys clock Joseph Lo
2013-07-29 22:47 ` Stephen Warren
2013-08-02 7:48 ` Joseph Lo
2013-08-02 20:24 ` Stephen Warren
2013-08-05 8:42 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 3/8] clk: tegra114: add LP1 suspend/resume support Joseph Lo
2013-07-29 22:51 ` Stephen Warren
2013-08-02 8:09 ` Joseph Lo
2013-08-02 20:32 ` Stephen Warren
2013-08-05 8:02 ` Joseph Lo
2013-08-05 17:00 ` Stephen Warren
2013-08-05 17:39 ` Stephen Warren
2013-08-06 9:10 ` Joseph Lo
2013-08-06 18:37 ` Stephen Warren
2013-08-07 9:12 ` Joseph Lo
2013-08-07 16:46 ` Stephen Warren
2013-08-08 2:23 ` Joseph Lo
2013-08-08 19:54 ` Stephen Warren
2013-08-09 9:23 ` Joseph Lo
2013-08-06 9:19 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 4/8] ARM: tegra: add common LP1 suspend support Joseph Lo
2013-07-29 23:13 ` Stephen Warren
2013-08-02 9:27 ` Joseph Lo
2013-08-02 20:40 ` Stephen Warren
2013-08-05 8:07 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 5/8] ARM: tegra30: add " Joseph Lo
2013-07-29 23:45 ` Stephen Warren
2013-08-05 6:46 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 6/8] ARM: tegra20: " Joseph Lo
2013-07-26 9:15 ` [PATCH 7/8] ARM: tegra114: " Joseph Lo
2013-07-29 23:53 ` Stephen Warren
2013-08-05 6:51 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 8/8] ARM: dts: tegra: enable LP1 suspend mode Joseph Lo
2013-07-27 16:12 ` [PATCH 0/8] ARM: tegra: support " Marc Dietrich
2013-07-27 16:20 ` Dmitry Osipenko
2013-07-27 18:09 ` Marc Dietrich
2013-07-27 18:26 ` Dmitry Osipenko
2013-07-27 18:29 ` Dmitry Osipenko
2013-07-27 19:03 ` Marc Dietrich
2013-07-27 19:11 ` Dmitry Osipenko
2013-07-30 9:49 ` Joseph Lo
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