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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2018-08-09 13:04:41 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2018-09-21 10:29:37 +0200 |
| commit | e4a8065910cd6b2e7e0448cc6431ca2906322389 (patch) | |
| tree | 73492991cfa40f994c20d761d476e6bc16304536 /freebsd/sys/dev/pci | |
| parent | Update to FreeBSD head 2017-08-01 (diff) | |
| download | rtems-libbsd-e4a8065910cd6b2e7e0448cc6431ca2906322389.tar.bz2 | |
Update to FreeBSD head 2017-10-01
Git mirror commit b2f0376b45428f13151d229c5ae9d4d8f74acbd1.
Update #3472.
Diffstat (limited to 'freebsd/sys/dev/pci')
| -rw-r--r-- | freebsd/sys/dev/pci/pci.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/freebsd/sys/dev/pci/pci.c b/freebsd/sys/dev/pci/pci.c index be4c626f..69497d2c 100644 --- a/freebsd/sys/dev/pci/pci.c +++ b/freebsd/sys/dev/pci/pci.c @@ -2906,13 +2906,21 @@ pci_read_bar(device_t dev, int reg, pci_addr_t *mapp, pci_addr_t *testvalp, * Determine the BAR's length by writing all 1's. The bottom * log_2(size) bits of the BAR will stick as 0 when we read * the value back. + * + * NB: according to the PCI Local Bus Specification, rev. 3.0: + * "Software writes 0FFFFFFFFh to both registers, reads them back, + * and combines the result into a 64-bit value." (section 6.2.5.1) + * + * Writes to both registers must be performed before attempting to + * read back the size value. */ + testval = 0; pci_write_config(dev, reg, 0xffffffff, 4); - testval = pci_read_config(dev, reg, 4); if (ln2range == 64) { pci_write_config(dev, reg + 4, 0xffffffff, 4); testval |= (pci_addr_t)pci_read_config(dev, reg + 4, 4) << 32; } + testval |= pci_read_config(dev, reg, 4); /* * Restore the original value of the BAR. We may have reprogrammed |