From 351b7c490700747d1dba1b0a10fbfe3448d11c35 Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Wed, 22 Mar 2017 11:01:48 -0700 Subject: ARM: omap2+: Revert omap-smp.c changes resetting CPU1 during boot Commit 3251885285e1 ("ARM: OMAP4+: Reset CPU1 properly for kexec") started unconditionally resetting CPU1 because of a kexec boot issue I was seeing earlier on omap4 when doing kexec boot between two different kernel versions. This caused issues on some systems. We should only reset CPU1 as a last resort option, and try to avoid it where possible. Doing an unconditional CPU1 reset causes issues for example when booting a bootloader configured secure OS running on CPU1 as reported by Andrew F. Davis . We can't completely remove the reset of CPU1 as it would break kexec booting from older kernels. But we can limit the CPU1 reset to cases where CPU1 is wrongly parked within the memory area used by the booting kernel. Then later on we can add support for parking CPU1 for kexec out of the SDRAM back to bootrom. So let's first fix the regression reported by Andrew by making CPU1 reset conditional. To do this, we need to: 1. Save configured AUX_CORE_BOOT_1 for later 2. Modify AUX_CORE_BOOT_0 reading code to for HS SoCs to return the whole register instead of the CPU mask 3. Check if CPU1 is wrongly parked into the booting kernel by the previous kernel and reset if needed Fixes: 3251885285e1 ("ARM: OMAP4+: Reset CPU1 properly for kexec") Reported-by: Andrew F. Davis Cc: Andrew F. Davis Cc: Keerthy Cc: Russell King Cc: Santosh Shilimkar Cc: Tero Kristo Tested-by: Keerthy Tested-by: Andrew F. Davis Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/omap-smc.S | 1 - 1 file changed, 1 deletion(-) (limited to 'arch/arm/mach-omap2/omap-smc.S') diff --git a/arch/arm/mach-omap2/omap-smc.S b/arch/arm/mach-omap2/omap-smc.S index fd90125bffc7..72506e6cf9e7 100644 --- a/arch/arm/mach-omap2/omap-smc.S +++ b/arch/arm/mach-omap2/omap-smc.S @@ -94,6 +94,5 @@ ENTRY(omap_read_auxcoreboot0) ldr r12, =0x103 dsb smc #0 - mov r0, r0, lsr #9 ldmfd sp!, {r2-r12, pc} ENDPROC(omap_read_auxcoreboot0) -- cgit v1.2.3