ARM: exynos: add debug_ll_io_init() call in exynos_init_io()

If the early MMU mapping of the UART happens to get booted out of the TLB between the start of paging_init() and when we finally re-add the UART at the very end of s3c_init_cpu(), we'll get a hang at bootup if we've got early_printk enabled. Avoid this hang by calling debug_ll_io_init() early. Without this patch, you can reliably reproduce a hang when early printk is enabled by adding flush_tlb_all() at the start of exynos_init_io(). After this patch the hang goes away. Signed-off-by: Doug Anderson <[email protected]> Acked-by: Kukjin Kim <[email protected]> Signed-off-by: Olof Johansson <[email protected]>
oohal · Jun 8, 2013 · 9c1fcdc · 9c1fcdc
1 parent fb565ff
commit 9c1fcdc
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c
@@ -386,6 +386,8 @@ int __init exynos_fdt_map_chipid(unsigned long node, const char *uname,
 
 void __init exynos_init_io(struct map_desc *mach_desc, int size)
 {
+	debug_ll_io_init();
+
 #ifdef CONFIG_OF
 	if (initial_boot_params)
 		of_scan_flat_dt(exynos_fdt_map_chipid, NULL);