firmware: provide infrastructure to make fw caching optional
authorVikram Mulukutla <markivx@codeaurora.org>
Tue, 2 Aug 2016 21:04:25 +0000 (14:04 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 2 Aug 2016 23:35:09 +0000 (19:35 -0400)
Some low memory systems with complex peripherals cannot afford to have
the relatively large firmware images taking up valuable memory during
suspend and resume.  Change the internal implementation of
firmware_class to disallow caching based on a configurable option.  In
the near future, variants of request_firmware will take advantage of
this feature.

Link: http://lkml.kernel.org/r/20160607164741.31849-3-stephen.boyd@linaro.org
[stephen.boyd@linaro.org: Drop firmware_desc design and use flags]
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/base/firmware_class.c

index 01d55723d82cfae3cfbfd518befea0352c1e873a..45ed20cefa105bfae926b841c53f6fa2cc1b05c9 100644 (file)
@@ -112,6 +112,7 @@ static inline long firmware_loading_timeout(void)
 #define FW_OPT_FALLBACK                0
 #endif
 #define FW_OPT_NO_WARN (1U << 3)
+#define FW_OPT_NOCACHE (1U << 4)
 
 struct firmware_cache {
        /* firmware_buf instance will be added into the below list */
@@ -1065,14 +1066,16 @@ static int assign_firmware_buf(struct firmware *fw, struct device *device,
         * should be fixed in devres or driver core.
         */
        /* don't cache firmware handled without uevent */
-       if (device && (opt_flags & FW_OPT_UEVENT))
+       if (device && (opt_flags & FW_OPT_UEVENT) &&
+           !(opt_flags & FW_OPT_NOCACHE))
                fw_add_devm_name(device, buf->fw_id);
 
        /*
         * After caching firmware image is started, let it piggyback
         * on request firmware.
         */
-       if (buf->fwc->state == FW_LOADER_START_CACHE) {
+       if (!(opt_flags & FW_OPT_NOCACHE) &&
+           buf->fwc->state == FW_LOADER_START_CACHE) {
                if (fw_cache_piggyback_on_request(buf->fw_id))
                        kref_get(&buf->ref);
        }