[PATCH v4 3/4] firmware: Drop bit ops in favor of simple state machine

[Daniel Wagner]

From: Daniel Wagner <daniel.wag...@bmw-carit.de>

We track the state of the loading with bit ops. Since the state machine
has only a couple of states and there are only a few simple state
transition we can model this simplify.

           UNKNOWN -> LOADING -> DONE | ABORTED

Signed-off-by: Daniel Wagner <daniel.wag...@bmw-carit.de>
Cc: Ming Lei <ming....@canonical.com>
Cc: Luis R. Rodriguez <mcg...@kernel.org>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/base/firmware_class.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index b11fbb0..7757c03 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -120,16 +120,18 @@ static void fw_status_init(struct fw_status *fw_st)
 
 static int __fw_status_check(struct fw_status *fw_st, unsigned long status)
 {
-       return test_bit(status, &fw_st->status);
+       return fw_st->status == status;
 }
 
 static int fw_status_wait_timeout(struct fw_status *fw_st, long timeout)
 {
+       unsigned long status;
        int ret;
 
        ret = wait_for_completion_interruptible_timeout(&fw_st->completion,
                                                        timeout);
-       if (ret == 0 && test_bit(FW_STATUS_ABORTED, &fw_st->status))
+       status = READ_ONCE(fw_st->status);
+       if (ret == 0 && status == FW_STATUS_ABORTED)
                return -ENOENT;
 
        return ret;
@@ -138,13 +140,11 @@ static int fw_status_wait_timeout(struct fw_status 
*fw_st, long timeout)
 static void __fw_status_set(struct fw_status *fw_st,
                          unsigned long status)
 {
-       set_bit(status, &fw_st->status);
+       WRITE_ONCE(fw_st->status, status);
 
        if (status == FW_STATUS_DONE ||
-                       status == FW_STATUS_ABORTED) {
-               clear_bit(FW_STATUS_LOADING, &fw_st->status);
+                       status == FW_STATUS_ABORTED)
                complete_all(&fw_st->completion);
-       }
 }
 
 #define fw_status_start(fw_st)                                 \
-- 
2.7.4