[PATCH] accel/qaic: Add support for PM callbacks

[PATCH] accel/qaic: Add support for PM callbacks

[Youssef Samir]

Add initial support for suspend and hibernation PM callbacks to QAIC.

Signed-off-by: Youssef Samir <youssef.abdulrahman@oss.qualcomm.com>
---
 drivers/accel/qaic/qaic.h          |  2 +
 drivers/accel/qaic/qaic_drv.c      | 89 ++++++++++++++++++++++++++++++
 drivers/accel/qaic/qaic_timesync.c |  9 +++
 drivers/accel/qaic/qaic_timesync.h |  3 +
 4 files changed, 103 insertions(+)

diff --git a/drivers/accel/qaic/qaic.h b/drivers/accel/qaic/qaic.h
index 820d133236dd..2bfc4ce203c5 100644
--- a/drivers/accel/qaic/qaic.h
+++ b/drivers/accel/qaic/qaic.h
@@ -161,6 +161,8 @@ struct qaic_device {
 	struct mhi_device	*qts_ch;
 	/* Work queue for tasks related to MHI "QAIC_TIMESYNC" channel */
 	struct workqueue_struct	*qts_wq;
+	/* MHI "QAIC_TIMESYNC_PERIODIC" channel device */
+	struct mhi_device	*mqts_ch;
 	/* Head of list of page allocated by MHI bootlog device */
 	struct list_head        bootlog;
 	/* MHI bootlog channel device */
diff --git a/drivers/accel/qaic/qaic_drv.c b/drivers/accel/qaic/qaic_drv.c
index e162f4b8a262..6cf0f42c9add 100644
--- a/drivers/accel/qaic/qaic_drv.c
+++ b/drivers/accel/qaic/qaic_drv.c
@@ -660,6 +660,92 @@ static const struct pci_error_handlers qaic_pci_err_handler = {
 	.reset_done = qaic_pci_reset_done,
 };
 
+static bool qaic_is_under_reset(struct qaic_device *qdev)
+{
+	int rcu_id;
+	bool ret;
+
+	rcu_id = srcu_read_lock(&qdev->dev_lock);
+	ret = qdev->dev_state != QAIC_ONLINE;
+	srcu_read_unlock(&qdev->dev_lock, rcu_id);
+	return ret;
+}
+
+static bool qaic_data_path_busy(struct qaic_device *qdev)
+{
+	int dev_rcu_id;
+	bool ret;
+	int i;
+
+	dev_rcu_id = srcu_read_lock(&qdev->dev_lock);
+	if (qdev->dev_state != QAIC_ONLINE) {
+		srcu_read_unlock(&qdev->dev_lock, dev_rcu_id);
+		return false;
+	}
+	for (i = 0; i < qdev->num_dbc; i++) {
+		struct dma_bridge_chan *dbc = &qdev->dbc[i];
+		unsigned long flags;
+		int ch_rcu_id;
+
+		ch_rcu_id = srcu_read_lock(&dbc->ch_lock);
+		if (!dbc->usr || !dbc->in_use) {
+			srcu_read_unlock(&dbc->ch_lock, ch_rcu_id);
+			continue;
+		}
+		spin_lock_irqsave(&dbc->xfer_lock, flags);
+		ret = !list_empty(&dbc->xfer_list);
+		spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+		srcu_read_unlock(&dbc->ch_lock, ch_rcu_id);
+		if (ret)
+			break;
+	}
+	srcu_read_unlock(&qdev->dev_lock, dev_rcu_id);
+	return ret;
+}
+
+static int qaic_pm_suspend(struct device *dev)
+{
+	struct qaic_device *qdev = pci_get_drvdata(to_pci_dev(dev));
+
+	dev_dbg(dev, "Suspending..\n");
+	if (qaic_data_path_busy(qdev)) {
+		dev_dbg(dev, "Device's datapath is busy. Aborting suspend..\n");
+		return -EBUSY;
+	}
+	if (qaic_is_under_reset(qdev)) {
+		dev_dbg(dev, "Device is under reset. Aborting suspend..\n");
+		return -EBUSY;
+	}
+	qaic_mqts_ch_stop_timer(qdev->mqts_ch);
+	qaic_pci_reset_prepare(qdev->pdev);
+	pci_save_state(qdev->pdev);
+	pci_disable_device(qdev->pdev);
+	pci_set_power_state(qdev->pdev, PCI_D3hot);
+	return 0;
+}
+
+static int qaic_pm_resume(struct device *dev)
+{
+	struct qaic_device *qdev = pci_get_drvdata(to_pci_dev(dev));
+	int ret;
+
+	dev_dbg(dev, "Resuming..\n");
+	pci_set_power_state(qdev->pdev, PCI_D0);
+	pci_restore_state(qdev->pdev);
+	ret = pci_enable_device(qdev->pdev);
+	if (ret) {
+		dev_err(dev, "pci_enable_device failed on resume %d\n", ret);
+		return ret;
+	}
+	pci_set_master(qdev->pdev);
+	qaic_pci_reset_done(qdev->pdev);
+	return 0;
+}
+
+static const struct dev_pm_ops qaic_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(qaic_pm_suspend, qaic_pm_resume)
+};
+
 static struct pci_driver qaic_pci_driver = {
 	.name = QAIC_NAME,
 	.id_table = qaic_ids,
@@ -667,6 +753,9 @@ static struct pci_driver qaic_pci_driver = {
 	.remove = qaic_pci_remove,
 	.shutdown = qaic_pci_shutdown,
 	.err_handler = &qaic_pci_err_handler,
+	.driver = {
+		.pm = &qaic_pm_ops,
+	},
 };
 
 static int __init qaic_init(void)
diff --git a/drivers/accel/qaic/qaic_timesync.c b/drivers/accel/qaic/qaic_timesync.c
index 3fac540f8e03..8af2475f4f36 100644
--- a/drivers/accel/qaic/qaic_timesync.c
+++ b/drivers/accel/qaic/qaic_timesync.c
@@ -171,6 +171,13 @@ static void qaic_timesync_timer(struct timer_list *t)
 		dev_err(mqtsdev->dev, "%s mod_timer error:%d\n", __func__, ret);
 }
 
+void qaic_mqts_ch_stop_timer(struct mhi_device *mhi_dev)
+{
+	struct mqts_dev *mqtsdev = dev_get_drvdata(&mhi_dev->dev);
+
+	timer_delete_sync(&mqtsdev->timer);
+}
+
 static int qaic_timesync_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id)
 {
 	struct qaic_device *qdev = pci_get_drvdata(to_pci_dev(mhi_dev->mhi_cntrl->cntrl_dev));
@@ -206,6 +213,7 @@ static int qaic_timesync_probe(struct mhi_device *mhi_dev, const struct mhi_devi
 	timer->expires = jiffies + msecs_to_jiffies(timesync_delay_ms);
 	add_timer(timer);
 	dev_set_drvdata(&mhi_dev->dev, mqtsdev);
+	qdev->mqts_ch = mhi_dev;
 
 	return 0;
 
@@ -221,6 +229,7 @@ static void qaic_timesync_remove(struct mhi_device *mhi_dev)
 {
 	struct mqts_dev *mqtsdev = dev_get_drvdata(&mhi_dev->dev);
 
+	mqtsdev->qdev->mqts_ch = NULL;
 	timer_delete_sync(&mqtsdev->timer);
 	mhi_unprepare_from_transfer(mqtsdev->mhi_dev);
 	kfree(mqtsdev->sync_msg);
diff --git a/drivers/accel/qaic/qaic_timesync.h b/drivers/accel/qaic/qaic_timesync.h
index 851b7acd43bb..77b9c2b55057 100644
--- a/drivers/accel/qaic/qaic_timesync.h
+++ b/drivers/accel/qaic/qaic_timesync.h
@@ -6,6 +6,9 @@
 #ifndef __QAIC_TIMESYNC_H__
 #define __QAIC_TIMESYNC_H__
 
+#include <linux/mhi.h>
+
 int qaic_timesync_init(void);
 void qaic_timesync_deinit(void);
+void qaic_mqts_ch_stop_timer(struct mhi_device *mhi_dev);
 #endif /* __QAIC_TIMESYNC_H__ */
-- 
2.43.0

Re: [PATCH] accel/qaic: Add support for PM callbacks

[kernel test robot]

Hi Youssef,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on drm-tip/drm-tip linus/master v6.18-rc2 next-20251023]
[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/Youssef-Samir/accel-qaic-Add-support-for-PM-callbacks/20251023-044052
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20251022204005.3888195-1-youssef.abdulrahman%40oss.qualcomm.com
patch subject: [PATCH] accel/qaic: Add support for PM callbacks
config: openrisc-allyesconfig (https://download.01.org/0day-ci/archive/20251023/202510231820.AMln6kY3-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251023/202510231820.AMln6kY3-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/202510231820.AMln6kY3-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/accel/qaic/qaic_drv.c:724:12: warning: 'qaic_pm_resume' defined but not used [-Wunused-function]
     724 | static int qaic_pm_resume(struct device *dev)
         |            ^~~~~~~~~~~~~~
>> drivers/accel/qaic/qaic_drv.c:703:12: warning: 'qaic_pm_suspend' defined but not used [-Wunused-function]
     703 | static int qaic_pm_suspend(struct device *dev)
         |            ^~~~~~~~~~~~~~~


vim +/qaic_pm_resume +724 drivers/accel/qaic/qaic_drv.c

   702	
 > 703	static int qaic_pm_suspend(struct device *dev)
   704	{
   705		struct qaic_device *qdev = pci_get_drvdata(to_pci_dev(dev));
   706	
   707		dev_dbg(dev, "Suspending..\n");
   708		if (qaic_data_path_busy(qdev)) {
   709			dev_dbg(dev, "Device's datapath is busy. Aborting suspend..\n");
   710			return -EBUSY;
   711		}
   712		if (qaic_is_under_reset(qdev)) {
   713			dev_dbg(dev, "Device is under reset. Aborting suspend..\n");
   714			return -EBUSY;
   715		}
   716		qaic_mqts_ch_stop_timer(qdev->mqts_ch);
   717		qaic_pci_reset_prepare(qdev->pdev);
   718		pci_save_state(qdev->pdev);
   719		pci_disable_device(qdev->pdev);
   720		pci_set_power_state(qdev->pdev, PCI_D3hot);
   721		return 0;
   722	}
   723	
 > 724	static int qaic_pm_resume(struct device *dev)
   725	{
   726		struct qaic_device *qdev = pci_get_drvdata(to_pci_dev(dev));
   727		int ret;
   728	
   729		dev_dbg(dev, "Resuming..\n");
   730		pci_set_power_state(qdev->pdev, PCI_D0);
   731		pci_restore_state(qdev->pdev);
   732		ret = pci_enable_device(qdev->pdev);
   733		if (ret) {
   734			dev_err(dev, "pci_enable_device failed on resume %d\n", ret);
   735			return ret;
   736		}
   737		pci_set_master(qdev->pdev);
   738		qaic_pci_reset_done(qdev->pdev);
   739		return 0;
   740	}
   741	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki