commit 6726d552a6912e88cf63fe2bda87b2efa0efc7d0 upstream.
Access to registers is guarded by ingenic_tcu_{enable,disable}_regs()
so the stop bit can be cleared before accessing a timer channel, but
those functions did not clear the stop bit on SoCs with a global TCU
clock gate.
Testing on the X1000 has revealed that the stop bits must be cleared
_and_ the global TCU clock must be ungated to access timer registers.
This appears to be the norm on Ingenic SoCs, and is specified in the
documentation for the X1000 and numerous JZ47xx SoCs.
If the stop bit isn't cleared, register writes don't take effect and
the system can be left in a broken state, eg. the watchdog timer may
not run.
The bug probably went unnoticed because stop bits are zeroed when
the SoC is reset, and the kernel does not set them unless a timer
gets disabled at runtime. However, it is possible that a bootloader
or a previous kernel (if using kexec) leaves the stop bits set and
we should not rely on them being cleared.
Fixing this is easy: have ingenic_tcu_{enable,disable}_regs() always
clear the stop bit, regardless of the presence of a global TCU gate.
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Paul Cercueil <paul@crapouillou.net>
Fixes: 4f89e4b8f1 ("clk: ingenic: Add driver for the TCU clocks")
Cc: stable@vger.kernel.org
Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Link: https://lore.kernel.org/r/20220617122254.738900-1-aidanmacdonald.0x0@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This device id table is passed to of_match_node() later on in probe, but
on CONFIG_OF=n builds of_match_node() doesn't do anything with the
arguments. Lets just mark the table unused so that the compiler doesn't
complain about this.
drivers/clk/ingenic/tcu.c:326:34: warning: unused variable 'ingenic_tcu_of_match' [-Wunused-const-variable]
static const struct of_device_id ingenic_tcu_of_match[] __initconst = {
^
1 warning generated.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lkml.kernel.org/r/20200528233837.70269-1-sboyd@kernel.org
There are a few manually-calculated variable-length struct allocations
left, this converts them to use struct_size. Found with the following
git grep command
git grep -A1 'kzalloc.*sizeof[^_].*+'
Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lkml.kernel.org/r/20190927185110.29897-1-steve@sk2.org
Acked-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
[sboyd@kernel.org: Add grep command]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
