5.4-stable review patch. If anyone has any objections, please let me know.
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From: Takashi Iwai tiwai@suse.de
[ Upstream commit c01f3815453e2d5f699ccd8c8c1f93a5b8669e59 ]
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 tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/pci/rme9652/hdsp.c | 6 ++++-- sound/pci/rme9652/hdspm.c | 6 ++++-- 2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/sound/pci/rme9652/hdsp.c b/sound/pci/rme9652/hdsp.c index c7b3e76ea2d26..87ada0c01f84d 100644 --- a/sound/pci/rme9652/hdsp.c +++ b/sound/pci/rme9652/hdsp.c @@ -1308,8 +1308,10 @@ 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 e34f07c9ff470..f5c7a214e17bc 100644 --- a/sound/pci/rme9652/hdspm.c +++ b/sound/pci/rme9652/hdspm.c @@ -1835,8 +1835,10 @@ 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)