PCI MSI capability is now a hardware verified feature and is enabled …

…by default.

- By default MSI-X remains disabled because it is still an experimental feature that has not been verified with real hardware testing. To use it the command-line options -e must be used.
- Added helpful warning for when the user attempts to start a second instance of the driver.

README.md

@@ -133,9 +133,9 @@ Options:
                  e.g. -d 13fe:00d7,0x11 -d 13fe:00d7,0x05
     -e vid:did,cap
                - Enable PCI/PCIe capability cap for device,
-                 e.g. -e 13fe:00d7,0x05
-                 By default all capabilities are disabled and require enabling to
-                 be activated (EXPERIMENTAL).
+                 e.g. -e 13fe:00d7,0x11
+                 By default MSI capability is enabled and MSI-X is disabled,
+                 and requires enabling to be activated (EXPERIMENTAL).
     -r delay   - Bus-off recovery delay timer duration (milliseconds).
                  If set to 0ms, then the bus-off recovery is disabled!
                  Default: 50ms
@@ -579,7 +579,7 @@ Current version output:
 
 ## PCIe MSI and MSI-X Capability Devices
 
-These capabilities are currently disabled by default. They are experimental and
+Some capabilities are currently disabled by default. They are experimental and
 have not been verified with real hardware.
 
 For PCIe devices that support capability 0x05 (MSI) and/or 0x11 (MSI-X), both
@@ -645,27 +645,20 @@ This shows the file `etc/profile` defining the needed environment variables so
 that the user console have them defined for dev-can-linux to find the PCI
 modules.
 
-For advanced user, if you wish to enable the 0x11 (MSI-X) capability or the
-the 0x05 (MSI) capability (if it's available), simply specific device and
-capability number with `-e` option program options to the `dev-can-linux` driver.
+For advanced user, if you wish to enable the 0x11 (MSI-X) capability (if it's
+available), simply specify device and capability number with `-e` option program
+options to the `dev-can-linux` driver. Note that capability MSI is enabled by
+default since it has been verified with real hardware, MSI-X is still unverified
+and experimental.
 
 To force MSI-X to be used:
 
     dev-can-linux -e vid:did,0x11
 
-To force MSI to be used:
-
-    dev-can-linux -e vid:did,0x05
-
 Note it is NOT recommended to enable capabilities, in production until we release
 a hardware tested and verified version. However this ability is provided for
 advanced users to adopt at their discretion.
 
-One final note on legacy MSI, PCI 3.0 onwards allow each interrupt to be masked
-individually. If this feature is not available on the device, that is, if Per
-Vector Masking (PVM) isn't supported, then currently the driver will revert to
-regular IRQ operation.
-
 
 ## Hardware Test Status
 

config/PROGRAM_VERSION

@@ -1 +1 @@
-1.2.0
+1.2.1

src/pci-capability.c

@@ -83,10 +83,14 @@ pci_err_t msix_init (struct pci_dev* dev) {
     int i;
 
     /*
-     * By default both MSI and MSI-X are disabled
+     * By default MSI-X is disabled because it is still an experimental feature
+     * that has not been validated with real hardware testing. To use it the
+     * command-line options -e must be used.
+     *
+     * MSI is a hardware verified feature and is enabled by default.
      */
 
-    bool disabled_msi = true;
+    bool disabled_msi = false;
     bool disabled_msix = true;
 
     pcie_init(dev);

src/pci.c

@@ -164,6 +164,8 @@ pci_err_t pci_enable_device (struct pci_dev* dev) {
         if (dev->hdl == NULL) {
             log_err("pci_device_attach error: %s\n", pci_strerror(r));
 
+            log_warn("only a single instance of the driver is allowed\n");
+
             return r;
         }
 
@@ -204,23 +206,7 @@ pci_err_t pci_enable_device (struct pci_dev* dev) {
          * Load capabilities
          */
 
-        bool device_cap_enabled = false;
-
-        int i;
-        for (i = 0; i < num_enable_device_cap_configs; ++i) {
-            if (enable_device_cap_config[i].vid == dev->vendor &&
-                enable_device_cap_config[i].did == dev->device &&
-                enable_device_cap_config[i].cap != -1)
-            {
-                device_cap_enabled = true;
-
-                break;
-            }
-        }
-
-        if (device_cap_enabled) {
-            msix_init(dev);
-        }
+        msix_init(dev);
 
         /*
          * Process bar info
@@ -378,23 +364,7 @@ void pci_disable_device (struct pci_dev* dev) {
         return;
     }
 
-    bool device_cap_enabled = false;
-
-    int i;
-    for (i = 0; i < num_enable_device_cap_configs; ++i) {
-        if (enable_device_cap_config[i].vid == dev->vendor &&
-            enable_device_cap_config[i].did == dev->device &&
-            enable_device_cap_config[i].cap != -1)
-        {
-            device_cap_enabled = true;
-
-            break;
-        }
-    }
-
-    if (device_cap_enabled) {
-        msix_uninit(dev);
-    }
+    msix_uninit(dev);
 
     if (dev != NULL) {
         if (dev->hdl != NULL) {

src/prints.c

@@ -197,9 +197,9 @@ void print_help (char* program_name) {
     printf("                 e.g. -d 13fe:00d7,0x11 -d 13fe:00d7,0x05\n");
     printf("    \e[1m-e vid:did,cap\e[m\n");
     printf("               - Enable PCI/PCIe capability cap for device,\n");
-    printf("                 e.g. -e 13fe:00d7,0x05\n");
-    printf("                 By default all capabilities are disabled and require enabling to\n");
-    printf("                 be activated (EXPERIMENTAL).\n");
+    printf("                 e.g. -e 13fe:00d7,0x11\n");
+    printf("                 By default MSI capability is enabled and MSI-X is disabled,\n");
+    printf("                 and requires enabling to be activated (EXPERIMENTAL).\n");
     printf("    \e[1m-b delay\e[m   - Bus-off recovery delay timer length (milliseconds).\n");
     printf("                 If set to 0ms, then the bus-off recovery is disabled!\n");
     printf("                 The netif transmission queue fault recovery is also set to this\n");