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From:   Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
To:     daniel.lezcano@linaro.org, rafael@kernel.org, rui.zhang@intel.com
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Subject: [PATCH v2 3/7] thermal: int340x: processor_thermal: Use non MSI interrupts
Date:   Mon, 17 Jul 2023 12:54:01 -0700
Message-Id: <20230717195405.730869-4-srinivas.pandruvada@linux.intel.com>
In-Reply-To: <20230717195405.730869-1-srinivas.pandruvada@linux.intel.com>
References: <20230717195405.730869-1-srinivas.pandruvada@linux.intel.com>
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There are issues in using MSI interrupts for processor thermal device.
The support is not consistent across generations. But the legacy PCI
interrupts work on all current generations.

Hence always use legacy PCI interrupts by default, instead of MSI.
Add a module param to use of MSI, so that MSI can be still used.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
v2:
Changed msi_enabled to type bool

 .../processor_thermal_device_pci.c            | 33 ++++++++++++-------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
index 5a2bcfff0a68..2be9b7f660d1 100644
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
@@ -15,6 +15,11 @@
 
 #define DRV_NAME "proc_thermal_pci"
 
+static bool msi_enabled;
+module_param(msi_enabled, bool, 0644);
+MODULE_PARM_DESC(msi_enabled,
+	"Use PCI MSI based interrupts for processor thermal device.");
+
 struct proc_thermal_pci {
 	struct pci_dev *pdev;
 	struct proc_thermal_device *proc_priv;
@@ -219,8 +224,6 @@ static int proc_thermal_pci_probe(struct pci_dev *pdev, const struct pci_device_
 		return ret;
 	}
 
-	pci_set_master(pdev);
-
 	INIT_DELAYED_WORK(&pci_info->work, proc_thermal_threshold_work_fn);
 
 	ret = proc_thermal_add(&pdev->dev, proc_priv);
@@ -248,16 +251,23 @@ static int proc_thermal_pci_probe(struct pci_dev *pdev, const struct pci_device_
 		goto err_ret_mmio;
 	}
 
-	/* request and enable interrupt */
-	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Failed to allocate vectors!\n");
-		goto err_ret_tzone;
-	}
-	if (!pdev->msi_enabled && !pdev->msix_enabled)
+	if (msi_enabled) {
+		pci_set_master(pdev);
+		/* request and enable interrupt */
+		ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "Failed to allocate vectors!\n");
+			goto err_ret_tzone;
+		}
+		if (!pdev->msi_enabled && !pdev->msix_enabled)
+			irq_flag = IRQF_SHARED;
+
+		irq =  pci_irq_vector(pdev, 0);
+	} else {
 		irq_flag = IRQF_SHARED;
+		irq = pdev->irq;
+	}
 
-	irq =  pci_irq_vector(pdev, 0);
 	ret = devm_request_threaded_irq(&pdev->dev, irq,
 					proc_thermal_irq_handler, NULL,
 					irq_flag, KBUILD_MODNAME, pci_info);
@@ -273,7 +283,8 @@ static int proc_thermal_pci_probe(struct pci_dev *pdev, const struct pci_device_
 	return 0;
 
 err_free_vectors:
-	pci_free_irq_vectors(pdev);
+	if (msi_enabled)
+		pci_free_irq_vectors(pdev);
 err_ret_tzone:
 	thermal_zone_device_unregister(pci_info->tzone);
 err_ret_mmio:
-- 
2.38.1