This is a note to let you know that I've just added the patch titled
ALSA: hdsp: Break infinite MIDI input flush loop
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-hdsp-break-infinite-midi-input-flush-loop.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e5ea36444ffd248be8821d41571725a965c68a9c
Author: Takashi Iwai <tiwai@xxxxxxx>
Date: Thu Aug 8 11:15:12 2024 +0200
ALSA: hdsp: Break infinite MIDI input flush loop
[ 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@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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)
