Commit 589d5726 authored Jan 23, 2017 by Darren Stevens Committed by Tejun Heo Jan 23, 2017

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>

parent d786b91f

drivers/ata/libata-sff.c

+13 −3

Original line number	Diff line number	Diff line
		@@ -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;
		}

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