From 589d572671fe7ca342d25cde07a0e310a6912971 Mon Sep 17 00:00:00 2001 From: Darren Stevens Date: Mon, 23 Jan 2017 14:33:36 -0500 Subject: [PATCH] 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 Signed-off-by: Tejun Heo Cc: Sergei Shtylyov --- drivers/ata/libata-sff.c | 16 +++++++++++++--- 1 file 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; }