ioat: do not perform removal actions at shutdown
Dan Williams [Tue, 6 Jan 2009 18:38:20 +0000 (11:38 -0700)]
Unregistering services should only happen at "remove" time.  This prevents
the device from being unregistered while dmaengine clients are still
active.  Also, the comment on ioat_remove is stale since removal is prevented
while a channel may be in use.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/ioat.c

index 9b16a3a..4105d65 100644 (file)
@@ -75,60 +75,10 @@ static int ioat_dca_enabled = 1;
 module_param(ioat_dca_enabled, int, 0644);
 MODULE_PARM_DESC(ioat_dca_enabled, "control support of dca service (default: 1)");
 
-static int ioat_setup_functionality(struct pci_dev *pdev, void __iomem *iobase)
-{
-       struct ioat_device *device = pci_get_drvdata(pdev);
-       u8 version;
-       int err = 0;
-
-       version = readb(iobase + IOAT_VER_OFFSET);
-       switch (version) {
-       case IOAT_VER_1_2:
-               device->dma = ioat_dma_probe(pdev, iobase);
-               if (device->dma && ioat_dca_enabled)
-                       device->dca = ioat_dca_init(pdev, iobase);
-               break;
-       case IOAT_VER_2_0:
-               device->dma = ioat_dma_probe(pdev, iobase);
-               if (device->dma && ioat_dca_enabled)
-                       device->dca = ioat2_dca_init(pdev, iobase);
-               break;
-       case IOAT_VER_3_0:
-               device->dma = ioat_dma_probe(pdev, iobase);
-               if (device->dma && ioat_dca_enabled)
-                       device->dca = ioat3_dca_init(pdev, iobase);
-               break;
-       default:
-               err = -ENODEV;
-               break;
-       }
-       if (!device->dma)
-               err = -ENODEV;
-       return err;
-}
-
-static void ioat_shutdown_functionality(struct pci_dev *pdev)
-{
-       struct ioat_device *device = pci_get_drvdata(pdev);
-
-       dev_err(&pdev->dev, "Removing dma and dca services\n");
-       if (device->dca) {
-               unregister_dca_provider(device->dca);
-               free_dca_provider(device->dca);
-               device->dca = NULL;
-       }
-
-       if (device->dma) {
-               ioat_dma_remove(device->dma);
-               device->dma = NULL;
-       }
-}
-
 static struct pci_driver ioat_pci_driver = {
        .name           = "ioatdma",
        .id_table       = ioat_pci_tbl,
        .probe          = ioat_probe,
-       .shutdown       = ioat_shutdown_functionality,
        .remove         = __devexit_p(ioat_remove),
 };
 
@@ -179,7 +129,29 @@ static int __devinit ioat_probe(struct pci_dev *pdev,
 
        pci_set_master(pdev);
 
-       err = ioat_setup_functionality(pdev, iobase);
+       switch (readb(iobase + IOAT_VER_OFFSET)) {
+       case IOAT_VER_1_2:
+               device->dma = ioat_dma_probe(pdev, iobase);
+               if (device->dma && ioat_dca_enabled)
+                       device->dca = ioat_dca_init(pdev, iobase);
+               break;
+       case IOAT_VER_2_0:
+               device->dma = ioat_dma_probe(pdev, iobase);
+               if (device->dma && ioat_dca_enabled)
+                       device->dca = ioat2_dca_init(pdev, iobase);
+               break;
+       case IOAT_VER_3_0:
+               device->dma = ioat_dma_probe(pdev, iobase);
+               if (device->dma && ioat_dca_enabled)
+                       device->dca = ioat3_dca_init(pdev, iobase);
+               break;
+       default:
+               err = -ENODEV;
+               break;
+       }
+       if (!device->dma)
+               err = -ENODEV;
+
        if (err)
                goto err_version;
 
@@ -198,17 +170,21 @@ err_enable_device:
        return err;
 }
 
-/*
- * It is unsafe to remove this module: if removed while a requested
- * dma is outstanding, esp. from tcp, it is possible to hang while
- * waiting for something that will never finish.  However, if you're
- * feeling lucky, this usually works just fine.
- */
 static void __devexit ioat_remove(struct pci_dev *pdev)
 {
        struct ioat_device *device = pci_get_drvdata(pdev);
 
-       ioat_shutdown_functionality(pdev);
+       dev_err(&pdev->dev, "Removing dma and dca services\n");
+       if (device->dca) {
+               unregister_dca_provider(device->dca);
+               free_dca_provider(device->dca);
+               device->dca = NULL;
+       }
+
+       if (device->dma) {
+               ioat_dma_remove(device->dma);
+               device->dma = NULL;
+       }
 
        kfree(device);
 }