[PATCH] DMI: allow omitting ident strings in DMI tables

From: Dmitry Torokhov
Date: Wed Dec 02 2009 - 22:12:55 EST


The purpose of dmi->ident is twofold - it may be used by DMI callback
functions when composing log messages; it is also used to determine
end of DMI table in dmi_check_system() and dmi_first_match(). However,
in case when callbacks are not interested in using ident at all it just
wastes memory. Let's consider entries with empty ident but initialized
first match slot as a valid entry and not as end-of-table marker.

Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>
---

CCed a few random people since they touched dmi code in the last few
months...

drivers/firmware/dmi_scan.c | 13 +++++++++++--
1 files changed, 11 insertions(+), 2 deletions(-)


diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 938100f..9116aa7 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -440,6 +440,15 @@ static bool dmi_matches(const struct dmi_system_id *dmi)
}

/**
+ * dmi_is_end_of_table - check for end-of-table marker
+ * @dmi: pointer to the dmi_system_id structure to check
+ */
+static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
+{
+ return dmi->ident == NULL && dmi->matches[0].slot == DMI_NONE;
+}
+
+/**
* dmi_check_system - check system DMI data
* @list: array of dmi_system_id structures to match against
* All non-null elements of the list must match
@@ -457,7 +466,7 @@ int dmi_check_system(const struct dmi_system_id *list)
int count = 0;
const struct dmi_system_id *d;

- for (d = list; d->ident; d++)
+ for (d = list; !dmi_is_end_of_table(d); d++)
if (dmi_matches(d)) {
count++;
if (d->callback && d->callback(d))
@@ -484,7 +493,7 @@ const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
{
const struct dmi_system_id *d;

- for (d = list; d->ident; d++)
+ for (d = list; !dmi_is_end_of_table(d); d++)
if (dmi_matches(d))
return d;

--
Dmitry
--
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