diff options
| -rw-r--r-- | src/drivers/bus/ecam.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/drivers/bus/ecam.c b/src/drivers/bus/ecam.c index 1d57bd2a0..376f34957 100644 --- a/src/drivers/bus/ecam.c +++ b/src/drivers/bus/ecam.c @@ -235,7 +235,7 @@ int ecam_write ( struct pci_device *pci, unsigned int location, if ( ( rc = ecam_access ( pci ) ) != 0 ) return rc; - /* Read from address */ + /* Write to address */ index = ( pci->busdevfn - ecam.range.start ); addr = ( ecam.regs + ( index * ECAM_SIZE ) + where ); switch ( len ) { @@ -252,6 +252,15 @@ int ecam_write ( struct pci_device *pci, unsigned int location, assert ( 0 ); } + /* Read from address, to guarantee completion of the write + * + * PCIe configuration space registers may not have read side + * effects. Reading back is therefore always safe to do, and + * guarantees that the write has reached the device. + */ + mb(); + ecam_read ( pci, location, &value ); + return 0; } |