ALSA: firewire-lib: replace in_interrupt() with in_softirq()

Tasklet is used to handle isochronous context of 1394 OHCI. The explicit
usage of in_softirq() may be preferable than in_interrupt().
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210611083425.61204-1-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-stream-trace.h

@@ -49,7 +49,7 @@ TRACE_EVENT(amdtp_packet,
 		__entry->data_blocks = data_blocks;
 		__entry->data_block_counter = data_block_counter,
 		__entry->packet_index = packet_index;
-		__entry->irq = !!in_interrupt();
+		__entry->irq = !!in_softirq();
 		__entry->index = index;
 	),
 	TP_printk(

sound/firewire/amdtp-stream.c

@@ -610,7 +610,7 @@ static void update_pcm_pointers(struct amdtp_stream *s,
 		// buffer associated to PCM substream to process PCM frames in the buffer, instead
 		// of receiving notification of period elapsed by poll wait.
 		if (!pcm->runtime->no_period_wakeup) {
-			if (in_interrupt()) {
+			if (in_softirq()) {
 				// In software IRQ context for 1394 OHCI.
 				snd_pcm_period_elapsed(pcm);
 			} else {
@@ -1026,7 +1026,7 @@ static void generate_pkt_descs(struct amdtp_stream *s, const __be32 *ctx_header,
 static inline void cancel_stream(struct amdtp_stream *s)
 {
 	s->packet_index = -1;
-	if (in_interrupt())
+	if (in_softirq())
 		amdtp_stream_pcm_abort(s);
 	WRITE_ONCE(s->pcm_buffer_pointer, SNDRV_PCM_POS_XRUN);
 }
@@ -1738,7 +1738,7 @@ unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
 	if (irq_target && amdtp_stream_running(irq_target)) {
 		// In software IRQ context, the call causes dead-lock to disable the tasklet
 		// synchronously.
-		if (!in_interrupt())
+		if (!in_softirq())
 			fw_iso_context_flush_completions(irq_target->context);
 	}