[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>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9c69b69..3ec558d 100644 (file)
--- 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;

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index aa48037..d408a3c 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -551,7 +551,14 @@ void
 pci_disable_device(struct pci_dev *dev)
 {
        u16 pci_command;
-       
+
+       if (dev->msi_enabled)
+               disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
+                       PCI_CAP_ID_MSI);
+       if (dev->msix_enabled)
+               disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
+                       PCI_CAP_ID_MSIX);
+
        pci_read_config_word(dev, PCI_COMMAND, &pci_command);
        if (pci_command & PCI_COMMAND_MASTER) {
                pci_command &= ~PCI_COMMAND_MASTER;

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 91c3775..62a8c22 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -163,6 +163,8 @@ struct pci_dev {
        unsigned int    no_msi:1;       /* device may not use msi */
        unsigned int    block_ucfg_access:1;    /* userspace config space access is blocked */
        unsigned int    broken_parity_status:1; /* Device generates false positive parity */
+       unsigned int    msi_enabled:1;
+       unsigned int    msix_enabled:1;
 
        u32             saved_config_space[16]; /* config space saved at suspend time */
        struct hlist_head saved_cap_space;