When unbinding PCI device mlx4 from its driver, the PCI device is
disabled by pci_disable_device() and the BARs (IO and memory) should
be disabled at the point. However, the memory BARs are still active
after the mlx4_core driver is unloaded as following logs show.
# lspci -vv -s 0003:0f:00.0
0003:0f:00.0 Network controller: Mellanox Technologies \
MT27500 Family [ConnectX-3]
Subsystem: Mellanox Technologies Device 0061
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- \
ParErr+ Stepping- SERR+ FastB2B- DisINTx+
:
Kernel driver in use: mlx4_core
# echo 0003:0f:00.0 > /sys/bus/pci/drivers/mlx4_core/unbind
# lspci -vv -s 0003:0f:00.0
0003:0f:00.0 Network controller: Mellanox Technologies \
MT27500 Family [ConnectX-3]
Subsystem: Mellanox Technologies Device 0061
Control: I/O- Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- \
ParErr+ Stepping- SERR+ FastB2B- DisINTx-
The patch turns off all BARs (IO and memory) in do_pci_disable_device().
Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
---
drivers/pci/pci.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 625a4ac..8d2924b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1496,12 +1496,14 @@ void __weak pcibios_penalize_isa_irq(int irq, int active) {}
static void do_pci_disable_device(struct pci_dev *dev)
{
- u16 pci_command;
+ u16 cmd, flags = (PCI_COMMAND_IO |
+ PCI_COMMAND_MEMORY |
+ PCI_COMMAND_MASTER);
- pci_read_config_word(dev, PCI_COMMAND, &pci_command);
- if (pci_command & PCI_COMMAND_MASTER) {
- pci_command &= ~PCI_COMMAND_MASTER;
- pci_write_config_word(dev, PCI_COMMAND, pci_command);
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+ if (cmd & flags) {
+ cmd &= ~flags;
+ pci_write_config_word(dev, PCI_COMMAND, cmd);
}
pcibios_disable_device(dev);
--
1.8.3.2
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