Re: [PATCH 07/13] clk: samsung: gs101: mark PERIC0 IP TOP gate clock as critical
From: Sam Protsenko <semen.protsenko@linaro.org>
Date: 2023-12-14 15:37:46
Also in:
linux-clk, linux-devicetree, linux-i2c, linux-samsung-soc, linux-serial, lkml
On Thu, Dec 14, 2023 at 4:52 AM Tudor Ambarus [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Testing USI8 I2C with an eeprom revealed that when the USI8 leaf clock is disabled it leads to the CMU_TOP PERIC0 IP gate clock disablement, which then makes the system hang. To prevent this, mark CLK_GOUT_CMU_PERIC0_IP as critical. Other clocks will be marked accordingly when tested. Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> --- drivers/clk/samsung/clk-gs101.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/clk/samsung/clk-gs101.c b/drivers/clk/samsung/clk-gs101.c index 3d194520b05e..08d80fca9cd6 100644 --- a/drivers/clk/samsung/clk-gs101.c +++ b/drivers/clk/samsung/clk-gs101.c@@ -1402,7 +1402,7 @@ static const struct samsung_gate_clock cmu_top_gate_clks[] __initconst = { "mout_cmu_peric0_bus", CLK_CON_GAT_GATE_CLKCMU_PERIC0_BUS, 21, 0, 0), GATE(CLK_GOUT_CMU_PERIC0_IP, "gout_cmu_peric0_ip", "mout_cmu_peric0_ip", - CLK_CON_GAT_GATE_CLKCMU_PERIC0_IP, 21, 0, 0), + CLK_CON_GAT_GATE_CLKCMU_PERIC0_IP, 21, CLK_IS_CRITICAL, 0),
This clock doesn't seem like a leaf clock. It's also not a bus clock. Leaving it always running makes the whole PERIC0 CMU clocked, which usually should be avoided. Is it possible that the system freezes because some other clock (which depends on peric0_ip) gets disabled as a consequence of disabling peric0_ip? Maybe it's some leaf clock which is not implemented yet in the clock driver? Just looks weird to me that the system hangs because of CMU IP clock disablement. It's usually something much more specific.
GATE(CLK_GOUT_CMU_PERIC1_BUS, "gout_cmu_peric1_bus",
"mout_cmu_peric1_bus", CLK_CON_GAT_GATE_CLKCMU_PERIC1_BUS,
21, 0, 0),
--
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