[PATCH 5.19 694/717] clk: bcm2835: Make peripheral PLLC critical

Greg Kroah-Hartman
2022-10-22T08:46:01Z

From: Maxime Ripard <maxime@cerno.tech>

[ Upstream commit 6c5422851d8be8c7451e968fd2e6da41b6109e17 ]

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>
---
drivers/clk/bcm/clk-bcm2835.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 9e9f8b242958..f1102b4c7e88 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1784,7 +1784,7 @@ 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.
--
2.35.1