e1000e: default IntMode based on kernel config & available hardware support
Based on a patch from Prabhakar Kushwaha <prabhakar@freescale.com>, set
appropriate default interrupt mode dependent on whether CONFIG_PCI_MSI
is enabled in the kernel configuration and if the hardware supports
MSI-X. Set the module parameter log message accordingly.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Cc: Jin Qing <b24347@freescale.com>
Cc: Prabhakar Kushwaha <prabhakar@freescale.com>
Cc: Jin Qing <b24347@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/e1000e/param.c b/drivers/net/ethernet/intel/e1000e/param.c
index 20e93b0..40664f5 100644
--- a/drivers/net/ethernet/intel/e1000e/param.c
+++ b/drivers/net/ethernet/intel/e1000e/param.c
@@ -113,11 +113,20 @@
#define MAX_ITR 100000
#define MIN_ITR 100
-/* IntMode (Interrupt Mode)
+/*
+ * IntMode (Interrupt Mode)
*
- * Valid Range: 0 - 2
+ * Valid Range: varies depending on kernel configuration & hardware support
*
- * Default Value: 2 (MSI-X)
+ * legacy=0, MSI=1, MSI-X=2
+ *
+ * When MSI/MSI-X support is enabled in kernel-
+ * Default Value: 2 (MSI-X) when supported by hardware, 1 (MSI) otherwise
+ * When MSI/MSI-X support is not enabled in kernel-
+ * Default Value: 0 (legacy)
+ *
+ * When a mode is specified that is not allowed/supported, it will be
+ * demoted to the most advanced interrupt mode available.
*/
E1000_PARAM(IntMode, "Interrupt Mode");
#define MAX_INTMODE 2
@@ -388,12 +397,33 @@
static struct e1000_option opt = {
.type = range_option,
.name = "Interrupt Mode",
- .err = "defaulting to 2 (MSI-X)",
- .def = E1000E_INT_MODE_MSIX,
- .arg = { .r = { .min = MIN_INTMODE,
- .max = MAX_INTMODE } }
+#ifndef CONFIG_PCI_MSI
+ .err = "defaulting to 0 (legacy)",
+ .def = E1000E_INT_MODE_LEGACY,
+ .arg = { .r = { .min = 0,
+ .max = 0 } }
+#endif
};
+#ifdef CONFIG_PCI_MSI
+ if (adapter->flags & FLAG_HAS_MSIX) {
+ opt.err = kstrdup("defaulting to 2 (MSI-X)",
+ GFP_KERNEL);
+ opt.def = E1000E_INT_MODE_MSIX;
+ opt.arg.r.max = E1000E_INT_MODE_MSIX;
+ } else {
+ opt.err = kstrdup("defaulting to 1 (MSI)", GFP_KERNEL);
+ opt.def = E1000E_INT_MODE_MSI;
+ opt.arg.r.max = E1000E_INT_MODE_MSI;
+ }
+
+ if (!opt.err) {
+ dev_err(&adapter->pdev->dev,
+ "Failed to allocate memory\n");
+ return;
+ }
+#endif
+
if (num_IntMode > bd) {
unsigned int int_mode = IntMode[bd];
e1000_validate_option(&int_mode, &opt, adapter);
@@ -401,6 +431,10 @@
} else {
adapter->int_mode = opt.def;
}
+
+#ifdef CONFIG_PCI_MSI
+ kfree(opt.err);
+#endif
}
{ /* Smart Power Down */
static const struct e1000_option opt = {