Hi Thomas,
On Mon, Jul 22, 2013 at 4:53 PM, Thomas Abraham
<thomas.abraham@xxxxxxxxxx> wrote:
> On 13 July 2013 04:57, Yadwinder Singh Brar <yadi.brar@xxxxxxxxxxx> 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 iotable_init tries to map UART again which is already mapped by
>> debug_ll_io_init() call in exynos_init_io() within same virtal address range as
>> requested later.
>
> debug_ll_io_init ioremaps debug uart address space with 4KB size
> whereas the exynos_init_io() function ioremaps a single 512KB memory
> size for all the four uart ports which envelops the mapping created by
> debug_ll_io_init. This is caught as a kernel bug.
>
Exactly !
>>
>> This issue seems to be occured after :
>> commit ee4de5d99aeac44f4507b7538b2b3faedc5205b9
>> ARM: 7781/1: mmu: Add debug_ll_io_init() mappings to early mappings
>>
>> This patch moves S3C_UART iodesc(in iodesc_list) inside CONFIG_DEBUG_LL check.
>
> Instead of moving, all the such iodesc entries for UART controller can
> be removed for all Samsung SoC's now since the Samsung uart driver
> does a ioremap during probe and any needed iomapping for earlyprintk
> is handled by debug_ll_io_init().
>
Ok, will do it.
TBH I was not sure about removing completely.
Thanks for review.
Regards,
Yadwinder
>>
>> Tested on 4412 and 5250 smdks.
>>
>> Signed-off-by: Yadwinder Singh Brar <yadi.brar@xxxxxxxxxxx>
>> ---
>> arch/arm/mach-exynos/common.c | 20 ++++++++++++++------
>> 1 files changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c
>> index 164685b..7f0591f 100644
>> --- a/arch/arm/mach-exynos/common.c
>> +++ b/arch/arm/mach-exynos/common.c
>> @@ -150,11 +150,6 @@ static struct map_desc exynos4_iodesc[] __initdata = {
>> .length = SZ_64K,
>> .type = MT_DEVICE,
>> }, {
>> - .virtual = (unsigned long)S3C_VA_UART,
>> - .pfn = __phys_to_pfn(EXYNOS4_PA_UART),
>> - .length = SZ_512K,
>> - .type = MT_DEVICE,
>> - }, {
>> .virtual = (unsigned long)S5P_VA_CMU,
>> .pfn = __phys_to_pfn(EXYNOS4_PA_CMU),
>> .length = SZ_128K,
>> @@ -185,6 +180,14 @@ static struct map_desc exynos4_iodesc[] __initdata = {
>> .length = SZ_4K,
>> .type = MT_DEVICE,
>> },
>> +#ifndef CONFIG_DEBUG_LL
>> + {
>> + .virtual = (unsigned long)S3C_VA_UART,
>> + .pfn = __phys_to_pfn(EXYNOS4_PA_UART),
>> + .length = SZ_512K,
>> + .type = MT_DEVICE,
>> + },
>> +#endif
>> };
>>
>> static struct map_desc exynos4_iodesc0[] __initdata = {
>> @@ -268,21 +271,26 @@ static struct map_desc exynos5_iodesc[] __initdata = {
>> .pfn = __phys_to_pfn(EXYNOS5_PA_PMU),
>> .length = SZ_64K,
>> .type = MT_DEVICE,
>> - }, {
>> + },
>> +#ifndef CONFIG_DEBUG_LL
>> + {
>> .virtual = (unsigned long)S3C_VA_UART,
>> .pfn = __phys_to_pfn(EXYNOS5_PA_UART),
>> .length = SZ_512K,
>> .type = MT_DEVICE,
>> },
>> +#endif
>> };
>>
>> static struct map_desc exynos5440_iodesc0[] __initdata = {
>> +#ifndef CONFIG_DEBUG_LL
>> {
>> .virtual = (unsigned long)S3C_VA_UART,
>> .pfn = __phys_to_pfn(EXYNOS5440_PA_UART0),
>> .length = SZ_512K,
>> .type = MT_DEVICE,
>> },
>> +#endif
>> };
>>
>> void exynos4_restart(enum reboot_mode mode, const char *cmd)
>> --
>> 1.7.0.4
>>
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