diff options
author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2009-01-24 10:14:37 (GMT) |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-01-24 11:41:20 (GMT) |
commit | 409dc360b49480b57869ffd457e4b95901b76b75 (patch) | |
tree | 23cfbdc67df8f1ec5edb73dc8b1736ff05a6b8da /arch/arm/common | |
parent | 02e0746ecc0e72482fe6f350cbb8b65d1d5fc40a (diff) | |
download | linux-fsl-qoriq-409dc360b49480b57869ffd457e4b95901b76b75.tar.xz |
[ARM] clkdev: fix clock matching
The old matching algorithm was too fuzzy, causing false positives.
For example, when asked for device D connection C1 and we only find
device D connection C2, we return that as a valid match despite the
connection names being different.
Change the algorithm such that:
An entry with a NULL ID is assumed to be a wildcard.
If an entry has a device ID, it must match
If an entry has a connection ID, it must match
However, we maintain the order of precidence while still only doing
a single pass over all entries: dev+con > dev only > con only.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/common')
-rw-r--r-- | arch/arm/common/clkdev.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/arch/arm/common/clkdev.c b/arch/arm/common/clkdev.c index 17a17b4..1037bba 100644 --- a/arch/arm/common/clkdev.c +++ b/arch/arm/common/clkdev.c @@ -24,6 +24,15 @@ static LIST_HEAD(clocks); static DEFINE_MUTEX(clocks_mutex); +/* + * Find the correct struct clk for the device and connection ID. + * We do slightly fuzzy matching here: + * An entry with a NULL ID is assumed to be a wildcard. + * If an entry has a device ID, it must match + * If an entry has a connection ID, it must match + * Then we take the most specific entry - with the following + * order of precidence: dev+con > dev only > con only. + */ static struct clk *clk_find(const char *dev_id, const char *con_id) { struct clk_lookup *p; @@ -31,13 +40,17 @@ static struct clk *clk_find(const char *dev_id, const char *con_id) int match, best = 0; list_for_each_entry(p, &clocks, node) { - if ((p->dev_id && !dev_id) || (p->con_id && !con_id)) - continue; match = 0; - if (p->dev_id) - match += 2 * (strcmp(p->dev_id, dev_id) == 0); - if (p->con_id) - match += 1 * (strcmp(p->con_id, con_id) == 0); + if (p->dev_id) { + if (!dev_id || strcmp(p->dev_id, dev_id)) + continue; + match += 2; + } + if (p->con_id) { + if (!con_id || strcmp(p->con_id, con_id)) + continue; + match += 1; + } if (match == 0) continue; |