6.17-stable review patch. If anyone has any objections, please let me know.
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From: Kunihiko Hayashi hayashi.kunihiko@socionext.com
[ Upstream commit 70e633bedeeb4a7290d3b1dd9d49cc2bae25a46f ]
When the driver is removed, the clocks are first enabled by calling pm_runtime_get_sync(), and then disabled with pm_runtime_put_sync().
If CONFIG_PM=y, clocks for this controller are disabled when it's in the idle state. So the clocks are properly disabled when the driver exits.
Othewise, the clocks are always enabled and the PM functions have no effect. Therefore, the driver exits without disabling the clocks.
# cat /sys/kernel/debug/clk/clk-pclk/clk_enable_count 18 # echo 1214a000.i2c > /sys/bus/platform/drivers/i2c_designware/bind # cat /sys/kernel/debug/clk/clk-pclk/clk_enable_count 20 # echo 1214a000.i2c > /sys/bus/platform/drivers/i2c_designware/unbind # cat /sys/kernel/debug/clk/clk-pclk/clk_enable_count 20
To ensure that the clocks can be disabled correctly even without CONFIG_PM=y, should add the following fixes:
- Replace with pm_runtime_put_noidle(), which only decrements the runtime PM usage count. - Call i2c_dw_prepare_clk(false) to explicitly disable the clocks.
Fixes: 7272194ed391f ("i2c-designware: add minimal support for runtime PM") Co-developed-by: Kohei Ito ito.kohei@socionext.com Signed-off-by: Kohei Ito ito.kohei@socionext.com Signed-off-by: Kunihiko Hayashi hayashi.kunihiko@socionext.com Tested-by: Jarkko Nikula jarkko.nikula@linux.intel.com Acked-by: Jarkko Nikula jarkko.nikula@linux.intel.com Signed-off-by: Wolfram Sang wsa+renesas@sang-engineering.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-designware-platdrv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index a35e4c64a1d46..b4bfdd2dd35e4 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -331,9 +331,11 @@ static void dw_i2c_plat_remove(struct platform_device *pdev) i2c_dw_disable(dev);
pm_runtime_dont_use_autosuspend(device); - pm_runtime_put_sync(device); + pm_runtime_put_noidle(device); dw_i2c_plat_pm_cleanup(dev);
+ i2c_dw_prepare_clk(dev, false); + i2c_dw_remove_lock_support(dev);
reset_control_assert(dev->rst);