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Commit 0430cafc authored by Daniel Wagner's avatar Daniel Wagner Committed by Greg Kroah-Hartman
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firmware: drop bit ops in favor of simple state machine 



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: default avatarDaniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: default avatarLuis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f52cc379

drivers/base/firmware_class.c

+5 −7
Original line number Diff line number Diff line
@@ -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;
@@ -141,13 +141,11 @@ 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)					\

	__fw_state_set(fw_st, FW_STATUS_LOADING)