[PATCH] PCI: disable msi mode in pci_disable_device

Brice said the pci_save_msi_state breaks his driver in his special usage
(not in suspend/resume), as pci_save_msi_state will disable msi mode. In
his usage, pci_save_state will be called at runtime, and later (after
the device operates for some time and has an error) pci_restore_state
will be called.
In another hand, suspend/resume needs disable msi mode, as device should
stop working completely. This patch try to workaround this issue.
Drivers are expected call pci_disable_device in suspend time after
pci_save_state.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9c69b6966e79..3ec558dc6523 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -453,9 +453,11 @@ static void enable_msi_mode(struct pci_dev *dev, int pos, int type)
                 /* Set enabled bits to single MSI & enable MSI_enable bit */
                 msi_enable(control, 1);
                 pci_write_config_word(dev, msi_control_reg(pos), control);
+                dev->msi_enabled = 1;
         } else {
                 msix_enable(control);
                 pci_write_config_word(dev, msi_control_reg(pos), control);
+                dev->msix_enabled = 1;
         }
         if (pci_find_capability(dev, PCI_CAP_ID_EXP)) {
                 /* PCI Express Endpoint device detected */
@@ -472,9 +474,11 @@ void disable_msi_mode(struct pci_dev *dev, int pos, int type)
                 /* Set enabled bits to single MSI & enable MSI_enable bit */
                 msi_disable(control);
                 pci_write_config_word(dev, msi_control_reg(pos), control);
+                dev->msi_enabled = 0;
         } else {
                 msix_disable(control);
                 pci_write_config_word(dev, msi_control_reg(pos), control);
+                dev->msix_enabled = 0;
         }
         if (pci_find_capability(dev, PCI_CAP_ID_EXP)) {
                 /* PCI Express Endpoint device detected */
@@ -549,7 +553,6 @@ int pci_save_msi_state(struct pci_dev *dev)
                 pci_read_config_dword(dev, pos + PCI_MSI_DATA_32, &cap[i++]);
         if (control & PCI_MSI_FLAGS_MASKBIT)
                 pci_read_config_dword(dev, pos + PCI_MSI_MASK_BIT, &cap[i++]);
-        disable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
         save_state->cap_nr = PCI_CAP_ID_MSI;
         pci_add_saved_cap(dev, save_state);
         return 0;
@@ -639,7 +642,6 @@ int pci_save_msix_state(struct pci_dev *dev)
         }
         dev->irq = temp;
 
-        disable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
         save_state->cap_nr = PCI_CAP_ID_MSIX;
         pci_add_saved_cap(dev, save_state);
         return 0;