i40e: fixup legacy interrupt handling

There were a number of little bugs in the error handling of irq setup, most of
which ended up panicing the kernel, and are addressed by this patch, along with
a couple formatting issues.

Legacy interrupts (including MSI) are used only in the case of failure to
allocate MSI-X interrupts.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 12 insertions, 6 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index a8c18faf1c54..270190ad7faa 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -4615,7 +4615,8 @@ static void i40e_fdir_setup(struct i40e_pf *pf)
         bool new_vsi = false;
         int err, i;
 
-        if (!(pf->flags & (I40E_FLAG_FDIR_ENABLED|I40E_FLAG_FDIR_ATR_ENABLED)))
+        if (!(pf->flags & (I40E_FLAG_FDIR_ENABLED |
+                           I40E_FLAG_FDIR_ATR_ENABLED)))
                 return;
 
         pf->atr_sample_rate = I40E_DEFAULT_ATR_SAMPLE_RATE;
@@ -5435,7 +5436,8 @@ static void i40e_init_interrupt_scheme(struct i40e_pf *pf)
         if (pf->flags & I40E_FLAG_MSIX_ENABLED) {
                 err = i40e_init_msix(pf);
                 if (err) {
-                        pf->flags &= ~(I40E_FLAG_RSS_ENABLED       |
+                        pf->flags &= ~(I40E_FLAG_MSIX_ENABLED      |
+                                        I40E_FLAG_RSS_ENABLED      |
                                         I40E_FLAG_MQ_ENABLED       |
                                         I40E_FLAG_DCB_ENABLED      |
                                         I40E_FLAG_SRIOV_ENABLED    |
@@ -5450,14 +5452,17 @@ static void i40e_init_interrupt_scheme(struct i40e_pf *pf)
 
         if (!(pf->flags & I40E_FLAG_MSIX_ENABLED) &&
             (pf->flags & I40E_FLAG_MSI_ENABLED)) {
+                dev_info(&pf->pdev->dev, "MSIX not available, trying MSI\n");
                 err = pci_enable_msi(pf->pdev);
                 if (err) {
-                        dev_info(&pf->pdev->dev,
-                                 "MSI init failed (%d), trying legacy.\n", err);
+                        dev_info(&pf->pdev->dev, "MSI init failed - %d\n", err);
                         pf->flags &= ~I40E_FLAG_MSI_ENABLED;
                 }
         }
 
+        if (!(pf->flags & (I40E_FLAG_MSIX_ENABLED | I40E_FLAG_MSI_ENABLED)))
+                dev_info(&pf->pdev->dev, "MSIX and MSI not available, falling back to Legacy IRQ\n");
+
         /* track first vector for misc interrupts */
         err = i40e_get_lump(pf, pf->irq_pile, 1, I40E_PILE_VALID_BIT-1);
 }
@@ -6110,8 +6115,9 @@ static int i40e_vsi_setup_vectors(struct i40e_vsi *vsi)
                 goto vector_setup_out;
         }
 
-        vsi->base_vector = i40e_get_lump(pf, pf->irq_pile,
-                                         vsi->num_q_vectors, vsi->idx);
+        if (vsi->num_q_vectors)
+                vsi->base_vector = i40e_get_lump(pf, pf->irq_pile,
+                                                 vsi->num_q_vectors, vsi->idx);
         if (vsi->base_vector < 0) {
                 dev_info(&pf->pdev->dev,
                          "failed to get q tracking for VSI %d, err=%d\n",