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firmware: drop bit ops in favor of simple state machine

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

	   UNKNOWN -> LOADING -> DONE | ABORTED

Because we don't use any bit ops on fw_state::status anymore we are able
to change the data type to enum fw_status and update the function
arguments accordingly.

READ_ONCE() and WRITE_ONCE() are propably not needed because there are a
lot of load and stores around fw_st->status. But let's make it explicit
and not be sorry later.

Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Daniel Wagner 2016-11-17 11:00:49 +01:00 committed by Greg Kroah-Hartman
parent f52cc37942
commit 0430cafcc4
1 changed files with 5 additions and 7 deletions
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12
drivers/base/firmware_class.c
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@ -112,7 +112,7 @@ static inline long firmware_loading_timeout(void)
*/
struct fw_state {
struct completion completion;
unsigned long status;
enum fw_status status;
};
static void fw_state_init(struct fw_state *fw_st)
@ -123,7 +123,7 @@ static void fw_state_init(struct fw_state *fw_st)
static int __fw_state_check(struct fw_state *fw_st, enum fw_status status)
{
return test_bit(status, &fw_st->status);
return fw_st->status == status;
}
static long __fw_state_wait_common(struct fw_state *fw_st, long timeout)
@ -132,7 +132,7 @@ static long __fw_state_wait_common(struct fw_state *fw_st, long timeout)
ret = wait_for_completion_interruptible_timeout(&fw_st->completion,
timeout);
if (ret != 0 && test_bit(FW_STATUS_ABORTED, &fw_st->status))
if (ret != 0 && READ_ONCE(fw_st->status) == FW_STATUS_ABORTED)
return -ENOENT;
return ret;
@ -141,12 +141,10 @@ static long __fw_state_wait_common(struct fw_state *fw_st, long timeout)
static void __fw_state_set(struct fw_state *fw_st,
enum fw_status 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);
if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
complete_all(&fw_st->completion);
}
}
#define fw_state_start(fw_st) \