From c01f3815453e2d5f699ccd8c8c1f93a5b8669e59 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 8 Aug 2024 11:15:12 +0200 Subject: ALSA: hdsp: Break infinite MIDI input flush loop The current MIDI input flush on HDSP and HDSPM drivers relies on the hardware reporting the right value. If the hardware doesn't give the proper value but returns -1, it may be stuck at an infinite loop. Add a counter and break if the loop is unexpectedly too long. Link: https://patch.msgid.link/20240808091513.31380-1-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/pci/rme9652/hdsp.c | 6 ++++-- sound/pci/rme9652/hdspm.c | 6 ++++-- 2 files changed, 8 insertions(+), 4 deletions(-) (limited to 'sound/pci') diff --git a/sound/pci/rme9652/hdsp.c b/sound/pci/rme9652/hdsp.c index e7d1b43471a2..713ca262a0e9 100644 --- a/sound/pci/rme9652/hdsp.c +++ b/sound/pci/rme9652/hdsp.c @@ -1298,8 +1298,10 @@ static int snd_hdsp_midi_output_possible (struct hdsp *hdsp, int id) static void snd_hdsp_flush_midi_input (struct hdsp *hdsp, int id) { - while (snd_hdsp_midi_input_available (hdsp, id)) - snd_hdsp_midi_read_byte (hdsp, id); + int count = 256; + + while (snd_hdsp_midi_input_available(hdsp, id) && --count) + snd_hdsp_midi_read_byte(hdsp, id); } static int snd_hdsp_midi_output_write (struct hdsp_midi *hmidi) diff --git a/sound/pci/rme9652/hdspm.c b/sound/pci/rme9652/hdspm.c index 56d335f0e196..c3f930a8f78d 100644 --- a/sound/pci/rme9652/hdspm.c +++ b/sound/pci/rme9652/hdspm.c @@ -1838,8 +1838,10 @@ static inline int snd_hdspm_midi_output_possible (struct hdspm *hdspm, int id) static void snd_hdspm_flush_midi_input(struct hdspm *hdspm, int id) { - while (snd_hdspm_midi_input_available (hdspm, id)) - snd_hdspm_midi_read_byte (hdspm, id); + int count = 256; + + while (snd_hdspm_midi_input_available(hdspm, id) && --count) + snd_hdspm_midi_read_byte(hdspm, id); } static int snd_hdspm_midi_output_write (struct hdspm_midi *hmidi) -- cgit v1.2.3-70-g09d2