kernel/linux.git/drivers/devfreq, branch v6.12.80

PM / devfreq: rockchip-dfi: double count on RK3588

2025-10-15T09:59:59+00:00

[ Upstream commit f89c7fb83ae95578e355bed1a7aeea5f3ca5a067 ] On RK3588 with LPDDR4X memory, the cycle count as returned by perf stat -a -e rockchip_ddr/cycles/ sleep 1 consistently reads half as much as what the actual DDR frequency is at. For a LPDDR4X module running at 2112MHz, I get more like 1056059916 cycles per second, which is almost bang-on half what it should be. No, I'm not mixing up megatransfers and megahertz. Consulting the downstream driver, this appears to be because the RK3588 hardware specifically (and RK3528 as well, for future reference) needs a multiplier of 2 to get to the correct frequency with everything but LPDDR5. The RK3588's actual memory bandwidth measurements in MB/s are correct however, as confirmed with stress-ng --stream. This makes me think the access counters are not affected in the same way. This tracks with the vendor kernel not multiplying the access counts either. Solve this by adding a new member to the dfi struct, which each SoC can set to whatever they want, but defaults to 1 if left unset by the SoC init functions. The event_get_count op can then use this multiplier if the cycle count is requested. The cycle multiplier is not used in rockchip_dfi_get_event because the vendor driver doesn't use it there either, and we don't do other actual bandwidth unit conversion stuff in there anyway. Fixes: 481d97ba61e1 ("PM / devfreq: rockchip-dfi: add support for RK3588") Signed-off-by: Nicolas Frattaroli Signed-off-by: Chanwoo Choi Link: https://lore.kernel.org/lkml/20250530-rk3588-dfi-improvements-v1-1-6e077c243a95@collabora.com/ Signed-off-by: Sasha Levin

PM / devfreq: mtk-cci: Fix potential error pointer dereference in probe()

2025-10-15T09:59:59+00:00

[ Upstream commit fc33bf0e097c6834646b98a7b3da0ae5b617f0f9 ] The drv->sram_reg pointer could be set to ERR_PTR(-EPROBE_DEFER) which would lead to a error pointer dereference. Use IS_ERR_OR_NULL() to check that the pointer is valid. Fixes: e09bd5757b52 ("PM / devfreq: mtk-cci: Handle sram regulator probe deferral") Signed-off-by: Dan Carpenter Signed-off-by: Chanwoo Choi Link: https://patchwork.kernel.org/project/linux-pm/patch/aJTNHz8kk8s6Q2os@stanley.mountain/ Signed-off-by: Sasha Levin

PM / devfreq: governor: Replace sscanf() with kstrtoul() in set_freq_store()

2025-08-20T16:30:23+00:00

[ Upstream commit 914cc799b28f17d369d5b4db3b941957d18157e8 ] Replace sscanf() with kstrtoul() in set_freq_store() and check the result to avoid invalid input. Signed-off-by: Lifeng Zheng Link: https://lore.kernel.org/lkml/20250421030020.3108405-2-zhenglifeng1@huawei.com/ Signed-off-by: Chanwoo Choi Signed-off-by: Sasha Levin

PM / devfreq: Fix a index typo in trans_stat

2025-08-15T10:13:37+00:00

[ Upstream commit 78c5845fbbf6aaeb9959c5fbaee5cc53ef5f38c2 ] Fixes: 4920ee6dcfaf ("PM / devfreq: Convert to use sysfs_emit_at() API") Signed-off-by: pls Link: https://patchwork.kernel.org/project/linux-pm/patch/20250515143100.17849-1-chanwoo@kernel.org/ Signed-off-by: Chanwoo Choi Signed-off-by: Sasha Levin

PM / devfreq: Check governor before using governor->name

2025-08-15T10:13:37+00:00

[ Upstream commit bab7834c03820eb11269bc48f07c3800192460d2 ] Commit 96ffcdf239de ("PM / devfreq: Remove redundant governor_name from struct devfreq") removes governor_name and uses governor->name to replace it. But devfreq->governor may be NULL and directly using devfreq->governor->name may cause null pointer exception. Move the check of governor to before using governor->name. Fixes: 96ffcdf239de ("PM / devfreq: Remove redundant governor_name from struct devfreq") Signed-off-by: Lifeng Zheng Link: https://lore.kernel.org/lkml/20250421030020.3108405-5-zhenglifeng1@huawei.com/ Signed-off-by: Chanwoo Choi Signed-off-by: Sasha Levin

PM / devfreq: imx-bus: Use of_property_present()

2024-09-04T16:23:56+00:00

Use of_property_present() to test for property presence rather than of_get_property(). This is part of a larger effort to remove callers of of_get_property() and similar functions. of_get_property() leaks the DT property data pointer which is a problem for dynamically allocated nodes which may be freed. Link: https://lore.kernel.org/lkml/20240731191312.1710417-11-robh@kernel.org/ Acked-by: Peng Fan Signed-off-by: Rob Herring (Arm) Signed-off-by: Chanwoo Choi

PM / devfreq: exynos: Use Use devm_clk_get_enabled() helpers

2024-09-04T15:33:00+00:00

The devm_clk_get_enabled() helpers: - call devm_clk_get() - call clk_prepare_enable() and register what is needed in order to call clk_disable_unprepare() when needed, as a managed resource. This simplifies the code and avoids the calls to clk_disable_unprepare(). While at it, use dev_err_probe consistently, and use its return value to return the error code. Link: https://lore.kernel.org/lkml/20240510094034.12493-1-linux.amoon@gmail.com/ Signed-off-by: Anand Moon Signed-off-by: Chanwoo Choi

PM/devfreq: governor: add missing MODULE_DESCRIPTION() macros

2024-09-04T15:33:00+00:00

make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/devfreq/governor_simpleondemand.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/devfreq/governor_performance.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/devfreq/governor_powersave.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/devfreq/governor_userspace.o Add all missing invocations of the MODULE_DESCRIPTION() macro. Link: https://lore.kernel.org/lkml/20240605-md-drivers-devfreq-v1-1-d01ae91b907e@quicinc.com/ Signed-off-by: Jeff Johnson Signed-off-by: Chanwoo Choi

PM / devfreq: exynos: Use DEFINE_SIMPLE_DEV_PM_OPS for PM functions

2024-05-08T15:30:37+00:00

This macro has the advantage over SET_SYSTEM_SLEEP_PM_OPS that we don't have to care about when the functions are actually used. Also make use of pm_sleep_ptr() to discard all PM_SLEEP related stuff if CONFIG_PM_SLEEP isn't enabled. Link: https://lore.kernel.org/lkml/20240417044459.1908-2-linux.amoon@gmail.com/ Signed-off-by: Anand Moon Signed-off-by: Chanwoo Choi

PM / devfreq: rk3399_dmc: Convert to platform remove callback returning void

2024-05-08T14:53:08+00:00

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Signed-off-by: Chanwoo Choi