* Grazvydas Ignotas <notasas@xxxxxxxxx> [150528 04:45]: > On Thu, May 28, 2015 at 1:55 AM, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > 8 <---------------------- > > From: Tony Lindgren <tony@xxxxxxxxxxx> > > Date: Wed, 27 May 2015 15:33:57 -0700 > > Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel > > > > We get a NULL pointer dereference on omap3 for thumb2 compiled kernels: > > > > Internal error: Oops: 80000005 [#1] SMP THUMB2 > > ... > > [<c046497b>] (_raw_spin_unlock_irqrestore) from [<c0024375>] > > (omap3_enter_idle_bm+0xc5/0x178) > > [<c0024375>] (omap3_enter_idle_bm) from [<c0374e63>] > > (cpuidle_enter_state+0x77/0x27c) > > [<c0374e63>] (cpuidle_enter_state) from [<c00627f1>] > > (cpu_startup_entry+0x155/0x23c) > > [<c00627f1>] (cpu_startup_entry) from [<c06b9a47>] > > (start_kernel+0x32f/0x338) > > [<c06b9a47>] (start_kernel) from [<8000807f>] (0x8000807f) > > > > The power management related assembly on moaps needs to interact with > > moaps -> omaps Thanks, fixed now. I also added a link for why ENDPROC is needed to the description. I'll apply the patch below into fixes today. Regards, Tony 8< ---------------------- From: Tony Lindgren <tony@xxxxxxxxxxx> Date: Wed, 27 May 2015 15:33:57 -0700 Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel We get a NULL pointer dereference on omap3 for thumb2 compiled kernels: Internal error: Oops: 80000005 [#1] SMP THUMB2 ... [<c046497b>] (_raw_spin_unlock_irqrestore) from [<c0024375>] (omap3_enter_idle_bm+0xc5/0x178) [<c0024375>] (omap3_enter_idle_bm) from [<c0374e63>] (cpuidle_enter_state+0x77/0x27c) [<c0374e63>] (cpuidle_enter_state) from [<c00627f1>] (cpu_startup_entry+0x155/0x23c) [<c00627f1>] (cpu_startup_entry) from [<c06b9a47>] (start_kernel+0x32f/0x338) [<c06b9a47>] (start_kernel) from [<8000807f>] (0x8000807f) The power management related assembly on omaps needs to interact with ARM mode bootrom code, so we need to keep most of the related assembly in ARM mode. Turns out this error is because of missing ENDPROC for assembly code as suggested by Stephen Boyd <sboyd@xxxxxxxxxxxxxx>. Let's add the missing ENDPROC in two places to sleep34xx.S, and also remove the earlier mystery code that was probably also caused by missing ENDPROC for earlier kernels. The reason why ENDPROC makes a difference is it sets .type and then the compiler knows what to do with the thumb bit as explained at: https://wiki.ubuntu.com/ARM/Thumb2PortingHowto Reported-by: Kevin Hilman <khilman@xxxxxxxxxx> Tested-by: Kevin Hilman <khilman@xxxxxxxxxx> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -203,23 +203,8 @@ save_context_wfi: */ ldr r1, kernel_flush blx r1 - /* - * The kernel doesn't interwork: v7_flush_dcache_all in particluar will - * always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. - * This sequence switches back to ARM. Note that .align may insert a - * nop: bx pc needs to be word-aligned in order to work. - */ - THUMB( .thumb ) - THUMB( .align ) - THUMB( bx pc ) - THUMB( nop ) - .arm - b omap3_do_wfi - -/* - * Local variables - */ +ENDPROC(omap34xx_cpu_suspend) omap3_do_wfi_sram_addr: .word omap3_do_wfi_sram kernel_flush: @@ -364,10 +349,7 @@ exit_nonoff_modes: * =================================== */ ldmfd sp!, {r4 - r11, pc} @ restore regs and return - -/* - * Local variables - */ +ENDPROC(omap3_do_wfi) sdrc_power: .word SDRC_POWER_V cm_idlest1_core: -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
