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authorDarren Stevens <darren@stevens-zone.net>2017-01-23 14:33:36 -0500
committerTejun Heo <tj@kernel.org>2017-01-23 14:35:17 -0500
commit589d572671fe7ca342d25cde07a0e310a6912971 (patch)
tree1320912a578de647f54598f3bfbb2d6faa1c9e83 /drivers/ata
parentd786b91f422c6ad4c0d9bb9c1bef2dd5008e3d9d (diff)
libata-sff: Don't scan disabled ports when checking for legacy mode.
libata-sff.c checks for legacy mode by testing if both primary and secondary ports on a controller are in legacy mode and selects legacy if either one is. However on some south bridge chips (e.g AMD SB600/SB700) the secondary port is not wired, and when it is disabled by setting the disable bit in the PCI header it appears as a fixed legacy port. Prevent incorrect detection by not testing ports that are marked as 'dummy' tj: Addressed Sergei's review points. Other style edits. Signed-off-by: Darren Stevens <darren@stevens-zone.net> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libata-sff.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 4441b5c5e4fb..2bd92dca3e62 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -2428,11 +2428,21 @@ int ata_pci_sff_activate_host(struct ata_host *host,
return rc;
if ((pdev->class >> 8) == PCI_CLASS_STORAGE_IDE) {
- u8 tmp8, mask;
+ u8 tmp8, mask = 0;
- /* TODO: What if one channel is in native mode ... */
+ /*
+ * ATA spec says we should use legacy mode when one
+ * port is in legacy mode, but disabled ports on some
+ * PCI hosts appear as fixed legacy ports, e.g SB600/700
+ * on which the secondary port is not wired, so
+ * ignore ports that are marked as 'dummy' during
+ * this check
+ */
pci_read_config_byte(pdev, PCI_CLASS_PROG, &tmp8);
- mask = (1 << 2) | (1 << 0);
+ if (!ata_port_is_dummy(host->ports[0]))
+ mask |= (1 << 0);
+ if (!ata_port_is_dummy(host->ports[1]))
+ mask |= (1 << 2);
if ((tmp8 & mask) != mask)
legacy_mode = 1;
}