clk: bcm2835: Make peripheral PLLC critical

[ Upstream commit ee487b9c7ae6aea8f2e37b91d640e6ce472d5123 ]

When testing for a series affecting the VEC, it was discovered that
turning off and on the VEC clock is crashing the system.

It turns out that, when disabling the VEC clock, it's the only child of
the PLLC-per clock which will also get disabled. The source of the crash
is PLLC-per being disabled.

It's likely that some other device might not take a clock reference that
it actually needs, but it's unclear which at this point. Let's make
PLLC-per critical so that we don't have that crash.

Reported-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220926084509.12233-1-maxime@cerno.tech
Reviewed-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index e650379b3230e035c5ffa5613edb42ed33ad2a8b..b4e6a79232330dbd2440ab3ef151a330dc4bd267 100644 (file)
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1756,7 +1756,7 @@ static const struct bcm2835_clk_desc clk_desc_array[] = {
                .load_mask = CM_PLLC_LOADPER,
                .hold_mask = CM_PLLC_HOLDPER,
                .fixed_divider = 1,
-               .flags = CLK_SET_RATE_PARENT),
+               .flags = CLK_IS_CRITICAL | CLK_SET_RATE_PARENT),
 
        /*
         * PLLD is the display PLL, used to drive DSI display panels.