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Subject[PATCH v3 2/3] firmware_class: Drop bit ops in favor of simple state machine
Date
From: Daniel Wagner <daniel.wagner@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.wagner@bmw-carit.de>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@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 f397026..d6cb33a 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
\
 
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