[v2] drm/bridge: cdns-dsi: Replace deprecated UNIVERSAL_DEV_PM_OPS()

[PATCH v2] drm/bridge: cdns-dsi: Replace deprecated UNIVERSAL_DEV_PM_OPS()

Posted by Vitor Soares 9 months ago

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
SET_RUNTIME_PM_OPS(), enabling suspend/resume handling through the
_enable()/_disable() hooks managed by the DRM framework for both
runtime and system-wide PM.

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>
---
v1 -> v2
 - Rely only on SET_RUNTIME_PM_OPS() for the PM.

 drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 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..5a31783fe856 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 +1279,9 @@ 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 const struct dev_pm_ops cdns_dsi_pm_ops = {
+	SET_RUNTIME_PM_OPS(cdns_dsi_suspend, cdns_dsi_resume, NULL)
+};
 
 static int cdns_dsi_drm_probe(struct platform_device *pdev)
 {
-- 
2.34.1

Re: [PATCH v2] drm/bridge: cdns-dsi: Replace deprecated UNIVERSAL_DEV_PM_OPS()

Posted by kernel test robot 9 months ago

Hi Vitor,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.15-rc5 next-20250508]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Vitor-Soares/drm-bridge-cdns-dsi-Replace-deprecated-UNIVERSAL_DEV_PM_OPS/20250508-001902
base:   linus/master
patch link:    https://lore.kernel.org/r/20250507161800.527464-1-ivitro%40gmail.com
patch subject: [PATCH v2] drm/bridge: cdns-dsi: Replace deprecated UNIVERSAL_DEV_PM_OPS()
config: s390-allyesconfig (https://download.01.org/0day-ci/archive/20250509/202505090233.0YCNNAzE-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250509/202505090233.0YCNNAzE-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202505090233.0YCNNAzE-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c:1148:12: warning: 'cdns_dsi_suspend' defined but not used [-Wunused-function]
    1148 | static int cdns_dsi_suspend(struct device *dev)
         |            ^~~~~~~~~~~~~~~~
>> drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c:1137:12: warning: 'cdns_dsi_resume' defined but not used [-Wunused-function]
    1137 | static int cdns_dsi_resume(struct device *dev)
         |            ^~~~~~~~~~~~~~~


vim +/cdns_dsi_suspend +1148 drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c

  1136	
> 1137	static int cdns_dsi_resume(struct device *dev)
  1138	{
  1139		struct cdns_dsi *dsi = dev_get_drvdata(dev);
  1140	
  1141		reset_control_deassert(dsi->dsi_p_rst);
  1142		clk_prepare_enable(dsi->dsi_p_clk);
  1143		clk_prepare_enable(dsi->dsi_sys_clk);
  1144	
  1145		return 0;
  1146	}
  1147	
> 1148	static int cdns_dsi_suspend(struct device *dev)
  1149	{
  1150		struct cdns_dsi *dsi = dev_get_drvdata(dev);
  1151	
  1152		clk_disable_unprepare(dsi->dsi_sys_clk);
  1153		clk_disable_unprepare(dsi->dsi_p_clk);
  1154		reset_control_assert(dsi->dsi_p_rst);
  1155		dsi->link_initialized = false;
  1156		return 0;
  1157	}
  1158	

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