Blackfin: fix accidental reset in some boot modes
We read the SWRST (Software Reset) register to get at the last reset
state, and then we may configure the DOUBLE_FAULT bit to control behavior
when a double fault occurs. But if the lower bits of the register is
already set (like UART boot mode on a BF54x), we inadvertently make the
system reset by writing to the SYSTEM_RESET field at the same time. So
make sure the lower 4 bits are always cleared.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c
index 6454bab..b2782ea 100644
--- a/arch/blackfin/kernel/setup.c
+++ b/arch/blackfin/kernel/setup.c
@@ -837,7 +837,8 @@
defined(CONFIG_BF538) || defined(CONFIG_BF539)
_bfin_swrst = bfin_read_SWRST();
#else
- _bfin_swrst = bfin_read_SYSCR();
+ /* Clear boot mode field */
+ _bfin_swrst = bfin_read_SYSCR() & ~0xf;
#endif
#ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT