RE: [v2 PATCH 0/2] EXYNOS: Fix low level debug support

[Kukjin Kim <kgene@kernel.org>]

Yadwinder Singh Brar wrote:
> 
> Presently, using exynos_defconfig with CONFIG_DEBUG_LL and
> CONFIG_EARLY_PRINTK
> on, kernel is not booting, we are getting following:
> 
> [    0.000000] ------------[ cut here ]------------
> [    0.000000] kernel BUG at mm/vmalloc.c:1134!
> [    0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
> [    0.000000] Modules linked in:
> [    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.11.0-rc1 #633
> [    0.000000] task: c052ec48 ti: c0524000 task.ti: c0524000
> [    0.000000] PC is at vm_area_add_early+0x54/0x94
> [    0.000000] LR is at add_static_vm_early+0xc/0x60
> 
> Its because exynos[4/5]_map_io() function ioremaps a single 512KB memory
> size for all the four uart ports which envelopes the mapping created by
> debug_ll_io_init(), called earlier in exynos_init_io().
> 
> This issue seems to be occured after :
> commit ee4de5d99aeac44f4507b7538b2b3faedc5205b9
> ARM: 7781/1: mmu: Add debug_ll_io_init() mappings to early mappings
> 
> This series removes static iodesc entries for UART controller for all
> Samsung
> SoC's and modifies pm debug code to save/restore only the selected debug
> uart
> registers.
> 
> changes since v1:
> - removed uart iodesc entires instead of just moving inside
> CONFIG_DEBUG_LL
>   check, as suggested by Thomas Abraham.
> - Fixed the possible issue after removing uart entries pointed by Tomasz
> Figa.
> 
> Tested doing suspend/resume on smdk5250.
> 
> Yadwinder Singh Brar (2):
>   ARM: SAMSUNG: pm: Save/restore only selected uart's registers
>   ARM: EXYNOS: Fix low level debug support
> 
>  arch/arm/mach-exynos/common.c |   26 --------------------------
>  arch/arm/plat-samsung/pm.c    |   14 +++-----------
>  2 files changed, 3 insertions(+), 37 deletions(-)

This series looks good to me, applied into -fixes.

Just note, I was looking at the static iodesc for UART because of booting
problem ;)

Anyway, thanks,
Kukjin