Don't reread the command register to see if enabling I/O or memory

decoding "took".  Other OS's that I checked do not do this and it breaks
some amdpm(4) devices.  Prior to 7.2 we did not honor the error returned
when this failed anyway, so this in effect restores previous behavior.

PR:		kern/137668
Tested by:	Aurelien Mere  aurelien.mere  amc-os.com
MFC after:	3 days

1 files changed, 1 insertions, 25 deletions

diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index 0b7b267..47aedbd 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -2149,62 +2149,38 @@ pci_disable_busmaster_method(device_t dev, device_t child)
 int
 pci_enable_io_method(device_t dev, device_t child, int space)
 {
-	uint16_t command;
 	uint16_t bit;
-	char *error;
-
-	bit = 0;
-	error = NULL;
 
 	switch(space) {
 	case SYS_RES_IOPORT:
 		bit = PCIM_CMD_PORTEN;
-		error = "port";
 		break;
 	case SYS_RES_MEMORY:
 		bit = PCIM_CMD_MEMEN;
-		error = "memory";
 		break;
 	default:
 		return (EINVAL);
 	}
 	pci_set_command_bit(dev, child, bit);
-	/* Some devices seem to need a brief stall here, what do to? */
-	command = PCI_READ_CONFIG(dev, child, PCIR_COMMAND, 2);
-	if (command & bit)
-		return (0);
-	device_printf(child, "failed to enable %s mapping!\n", error);
-	return (ENXIO);
+	return (0);
 }
 
 int
 pci_disable_io_method(device_t dev, device_t child, int space)
 {
-	uint16_t command;
 	uint16_t bit;
-	char *error;
-
-	bit = 0;
-	error = NULL;
 
 	switch(space) {
 	case SYS_RES_IOPORT:
 		bit = PCIM_CMD_PORTEN;
-		error = "port";
 		break;
 	case SYS_RES_MEMORY:
 		bit = PCIM_CMD_MEMEN;
-		error = "memory";
 		break;
 	default:
 		return (EINVAL);
 	}
 	pci_clear_command_bit(dev, child, bit);
-	command = PCI_READ_CONFIG(dev, child, PCIR_COMMAND, 2);
-	if (command & bit) {
-		device_printf(child, "failed to disable %s mapping!\n", error);
-		return (ENXIO);
-	}
 	return (0);
 }