ARM: OMAP4: PM: Warn users about usage of older bootloaders (60480098) · Commits · 戴 / test

OMAP4 CHIP level PM works only with newer bootloaders. The dependency on the bootloader comes from the fact that the kernel is missing reset and initialization code for some devices. While the right thing to do is to add reset and init code in the kernel, for some co-processor IP blocks like DSP and IVA it means downloading firmware into each one of them to execute idle instructions. While a feasible solution is worked upon on how such IP blocks can be better handled in the kernel, in the interim, to avoid any further frustration to users testing PM on OMAP4 and finding it broken, warn them about the bootloader being a possible cause. Signed-off-by:

Rajendra Nayak <rnayak@ti.com> Cc: Tero Kristo <t-kristo@ti.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: R Sricharan <r.sricharan@ti.com> [paul@pwsan.com: tweaked warning messages and comments slightly] Acked-by:

Kevin Hilman <khilman@linaro.org> [paul@pwsan.com: fixed checkpatch warning] Signed-off-by:

Paul Walmsley <paul@pwsan.com>

arch/arm/mach-omap2/pm44xx.c

+19 −2

Original line number	Diff line number	Diff line
		@@ -77,10 +77,20 @@ static int omap4_pm_suspend(void)
		omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
		pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->saved_logic_state);
		}
		if (ret)
		if (ret) {
		pr_crit("Could not enter target state in pm_suspend\n");
		else
		/*
		* OMAP4 chip PM currently works only with certain (newer)
		* versions of bootloaders. This is due to missing code in the
		* kernel to properly reset and initialize some devices.
		* Warn the user about the bootloader version being one of the
		* possible causes.
		* http://www.spinics.net/lists/arm-kernel/msg218641.html
		*/
		pr_warn("A possible cause could be an old bootloader - try u-boot >= v2012.07\n");
		} else {
		pr_info("Successfully put all powerdomains to target state\n");
		}

		return 0;
		}
		@@ -146,6 +156,13 @@ int __init omap4_pm_init(void)
		}

		pr_err("Power Management for TI OMAP4.\n");
		/*
		* OMAP4 chip PM currently works only with certain (newer)
		* versions of bootloaders. This is due to missing code in the
		* kernel to properly reset and initialize some devices.
		* http://www.spinics.net/lists/arm-kernel/msg218641.html
		*/
		pr_warn("OMAP4 PM: u-boot >= v2012.07 is required for full PM support\n");

		ret = pwrdm_for_each(pwrdms_setup, NULL);
		if (ret) {

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