Hi,
On 28/04/2025 12:40, Vitor Soares wrote:
From: Vitor Soares vitor.soares@toradex.com
The deprecated UNIVERSAL_DEV_PM_OPS() macro uses the provided callbacks for both runtime PM and system sleep. This causes the DSI clocks to be disabled twice: once during runtime suspend and again during system suspend, resulting in a WARN message from the clock framework when attempting to disable already-disabled clocks.
[ 84.384540] clk:231:5 already disabled [ 84.388314] WARNING: CPU: 2 PID: 531 at /drivers/clk/clk.c:1181 clk_core_disable+0xa4/0xac ... [ 84.579183] Call trace: [ 84.581624] clk_core_disable+0xa4/0xac [ 84.585457] clk_disable+0x30/0x4c [ 84.588857] cdns_dsi_suspend+0x20/0x58 [cdns_dsi] [ 84.593651] pm_generic_suspend+0x2c/0x44 [ 84.597661] ti_sci_pd_suspend+0xbc/0x15c [ 84.601670] dpm_run_callback+0x8c/0x14c [ 84.605588] __device_suspend+0x1a0/0x56c [ 84.609594] dpm_suspend+0x17c/0x21c [ 84.613165] dpm_suspend_start+0xa0/0xa8 [ 84.617083] suspend_devices_and_enter+0x12c/0x634 [ 84.621872] pm_suspend+0x1fc/0x368
To address this issue, replace UNIVERSAL_DEV_PM_OPS() with DEFINE_RUNTIME_DEV_PM_OPS(), which avoids redundant suspend/resume calls by checking if the device is already runtime suspended.
Cc: stable@vger.kernel.org # 6.1.x Fixes: e19233955d9e ("drm/bridge: Add Cadence DSI driver") Signed-off-by: Vitor Soares vitor.soares@toradex.com
drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index b022dd6e6b6e..62179e55e032 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -1258,7 +1258,7 @@ static const struct mipi_dsi_host_ops cdns_dsi_ops = { .transfer = cdns_dsi_transfer, }; -static int __maybe_unused cdns_dsi_resume(struct device *dev) +static int cdns_dsi_resume(struct device *dev) { struct cdns_dsi *dsi = dev_get_drvdata(dev); @@ -1269,7 +1269,7 @@ static int __maybe_unused cdns_dsi_resume(struct device *dev) return 0; } -static int __maybe_unused cdns_dsi_suspend(struct device *dev) +static int cdns_dsi_suspend(struct device *dev) { struct cdns_dsi *dsi = dev_get_drvdata(dev); @@ -1279,8 +1279,8 @@ static int __maybe_unused cdns_dsi_suspend(struct device *dev) return 0; } -static UNIVERSAL_DEV_PM_OPS(cdns_dsi_pm_ops, cdns_dsi_suspend, cdns_dsi_resume,
NULL);+static DEFINE_RUNTIME_DEV_PM_OPS(cdns_dsi_pm_ops, cdns_dsi_suspend,
cdns_dsi_resume, NULL);
I'm not sure if this, or the UNIVERSAL_DEV_PM_OPS, is right here. When the system is suspended, the bridge drivers will get a call to the *_disable() hook, which then disables the device. If the bridge driver would additionally do something in its system suspend hook, it would conflict with normal disable path.
I think bridges/panels should only deal with runtime PM.
Tomi