[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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