[PATCH v3 5/8] pci: ensure device does ignore BAR mangling

[Sebastian Hesselbarth]

Disable access to PCI devices I/O and memory regions while
mangling BAR registers.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
---
Changelog:
v2->v3:
- new patch      

Cc: barebox at lists.infradead.org
Cc: Antony Pavlov <antonynpavlov at gmail.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
Cc: Lucas Stach <l.stach at pengutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Cc: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
---
 drivers/pci/pci.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index f58e2c98f185..b64f25d13282 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -191,6 +191,10 @@ unsigned int pci_scan_bus(struct pci_bus *bus)
 			continue;
 		}
 
+		pci_read_config_byte(dev, PCI_COMMAND, &cmd);
+		pci_write_config_byte(dev, PCI_COMMAND,
+				      cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY));
+
 		for (bar = 0; bar < 6; bar++) {
 			resource_size_t last_addr;
 
@@ -233,6 +237,7 @@ unsigned int pci_scan_bus(struct pci_bus *bus)
 				bar++;
 		}
 
+		pci_write_config_byte(dev, PCI_COMMAND, cmd);
 		list_add_tail(&dev->bus_list, &bus->devices);
 		pci_register_device(dev);
 	}
-- 
2.0.0