Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5017b285 authored by Jani Nikula's avatar Jani Nikula Committed by Linus Torvalds
Browse files

dmi: add support for exact DMI matches in addition to substring matching 



dmi_match() considers a substring match to be a successful match.  This is
not always sufficient to distinguish between DMI data for different
systems.  Add support for exact string matching using strcmp() in addition
to the substring matching using strstr().

The specific use case in the i915 driver is to allow us to use an exact
match for D510MO, without also incorrectly matching D510MOV:

  {
	.ident = "Intel D510MO",
	.matches = {
		DMI_MATCH(DMI_BOARD_VENDOR, "Intel"),
		DMI_EXACT_MATCH(DMI_BOARD_NAME, "D510MO"),
	},
  }

Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Cc: <annndddrr@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Cornel Panceac <cpanceac@gmail.com>
Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 45c64940

drivers/firmware/dmi_scan.c

+9 −3
Original line number Diff line number Diff line
@@ -551,9 +551,15 @@ static bool dmi_matches(const struct dmi_system_id *dmi) 
		int s = dmi->matches[i].slot;

		if (s == DMI_NONE)

			break;

		if (dmi_ident[s]

		    && strstr(dmi_ident[s], dmi->matches[i].substr))

		if (dmi_ident[s]) {

			if (!dmi->matches[i].exact_match &&

			    strstr(dmi_ident[s], dmi->matches[i].substr))

				continue;

			else if (dmi->matches[i].exact_match &&

				 !strcmp(dmi_ident[s], dmi->matches[i].substr))

				continue;

		}



		/* No match */

		return false;

	}

include/linux/mod_devicetable.h

+4 −2
Original line number Diff line number Diff line
@@ -456,7 +456,8 @@ enum dmi_field { 
};



struct dmi_strmatch {

	unsigned char slot;

	unsigned char slot:7;

	unsigned char exact_match:1;

	char substr[79];

};
@@ -474,7 +475,8 @@ struct dmi_system_id { 
 */

#define dmi_device_id dmi_system_id



#define DMI_MATCH(a, b)	{ a, b }

#define DMI_MATCH(a, b)	{ .slot = a, .substr = b }

#define DMI_EXACT_MATCH(a, b)	{ .slot = a, .substr = b, .exact_match = 1 }



#define PLATFORM_NAME_SIZE	20

#define PLATFORM_MODULE_PREFIX	"platform:"