From 0430cafcc4fb632beeeab42f8817542dcf6901ce Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Thu, 17 Nov 2016 11:00:49 +0100 Subject: [PATCH] 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 Signed-off-by: Daniel Wagner Acked-by: Luis R. Rodriguez Signed-off-by: Greg Kroah-Hartman --- drivers/base/firmware_class.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index 4f5105f57521..45a20dd31c25 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -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) \ -- 2.20.1