[PATCH 02/10] ALSA: firewire-lib: use macro for maximum value of second in 1394 OHCI isoc descriptor

Takashi Sakamoto o-takashi at sakamocchi.jp
Fri May 8 06:36:27 CEST 2020


In descriptor of isochronous context in 1394 OHCI, the field of second
has 3 bit, thus the maximum value is 8. The value is used for correct
cycle calculation.

This commit replaces hard-coded value with macro to obsolete magic
number.

Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/firewire/amdtp-stream.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 37d38efb4c87..fcde01b54d11 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -20,6 +20,8 @@
 #define CYCLES_PER_SECOND	8000
 #define TICKS_PER_SECOND	(TICKS_PER_CYCLE * CYCLES_PER_SECOND)
 
+#define OHCI_MAX_SECOND		8
+
 /* Always support Linux tracing subsystem. */
 #define CREATE_TRACE_POINTS
 #include "amdtp-stream-trace.h"
@@ -680,8 +682,8 @@ static inline u32 compute_cycle_count(__be32 ctx_header_tstamp)
 static inline u32 increment_cycle_count(u32 cycle, unsigned int addend)
 {
 	cycle += addend;
-	if (cycle >= 8 * CYCLES_PER_SECOND)
-		cycle -= 8 * CYCLES_PER_SECOND;
+	if (cycle >= OHCI_MAX_SECOND * CYCLES_PER_SECOND)
+		cycle -= OHCI_MAX_SECOND * CYCLES_PER_SECOND;
 	return cycle;
 }
 
-- 
2.25.1



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