Hello, If on the kernel command line the parameter "earlyprintk" is written twice, then setup_early_printk is called twice. This can happen for example with the option CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND is selected, and the "earlyprintk" is passed from the ATAG_CMDLINE and from the dtb.
This lead to an infinite loop on the message "Booting Linux on physical CPU 0" displayed from smp_setup_processor_id() in arch/arm/kernel/setup.c. This behavior as been reproduced on ARMv7 architecture (Armada XP and Armada 370), and on a ARMv5 one (AT91SAMG35 thanks to Richard Genoud), with and with CONFIG_SMP selected. After some investigation I found that the problem happened when the early_console is register for the second time in file kernel/printk.c on line 2310 when the function console_lock() is called, and in this function I managed to have traces until the call to down(&console_sem) one line 1922. Keep in mind that I had this information using printk so maybe it was not the best way to debug the console! I didn't had other platform that ARM one for testing this behavior, so I don't know if this bug is specific to ARM. If you think it is something specific to ARM then I propose the patch in the following email. Any feedback on this issue would be welcome Thanks, Gregory CLEMENT (1): ARM: don't allow to register the early_console twice arch/arm/kernel/early_printk.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/