This is a note to let you know that I've just added the patch titled
ALSA: emu10k1: don't deadlock in proc-functions
to the 3.10-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-emu10k1-don-t-deadlock-in-proc-functions.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 91bf0c2dcb935a87e5c0795f5047456b965fd143 Mon Sep 17 00:00:00 2001
From: Michael Gernoth <michael@xxxxxxxxxxx>
Date: Thu, 9 Apr 2015 23:42:15 +0200
Subject: ALSA: emu10k1: don't deadlock in proc-functions
From: Michael Gernoth <michael@xxxxxxxxxxx>
commit 91bf0c2dcb935a87e5c0795f5047456b965fd143 upstream.
The functions snd_emu10k1_proc_spdif_read and snd_emu1010_fpga_read
acquire the emu_lock before accessing the FPGA. The function used
to access the FPGA (snd_emu1010_fpga_read) also tries to take
the emu_lock which causes a deadlock.
Remove the outer locking in the proc-functions (guarding only the
already safe fpga read) to prevent this deadlock.
[removed superfluous flags variables too -- tiwai]
Signed-off-by: Michael Gernoth <michael@xxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/pci/emu10k1/emuproc.c | 12 ------------
1 file changed, 12 deletions(-)
--- a/sound/pci/emu10k1/emuproc.c
+++ b/sound/pci/emu10k1/emuproc.c
@@ -241,31 +241,22 @@ static void snd_emu10k1_proc_spdif_read(
struct snd_emu10k1 *emu = entry->private_data;
u32 value;
u32 value2;
- unsigned long flags;
u32 rate;
if (emu->card_capabilities->emu_model) {
- spin_lock_irqsave(&emu->emu_lock, flags);
snd_emu1010_fpga_read(emu, 0x38, &value);
- spin_unlock_irqrestore(&emu->emu_lock, flags);
if ((value & 0x1) == 0) {
- spin_lock_irqsave(&emu->emu_lock, flags);
snd_emu1010_fpga_read(emu, 0x2a, &value);
snd_emu1010_fpga_read(emu, 0x2b, &value2);
- spin_unlock_irqrestore(&emu->emu_lock, flags);
rate = 0x1770000 / (((value << 5) | value2)+1);
snd_iprintf(buffer, "ADAT Locked : %u\n", rate);
} else {
snd_iprintf(buffer, "ADAT Unlocked\n");
}
- spin_lock_irqsave(&emu->emu_lock, flags);
snd_emu1010_fpga_read(emu, 0x20, &value);
- spin_unlock_irqrestore(&emu->emu_lock, flags);
if ((value & 0x4) == 0) {
- spin_lock_irqsave(&emu->emu_lock, flags);
snd_emu1010_fpga_read(emu, 0x28, &value);
snd_emu1010_fpga_read(emu, 0x29, &value2);
- spin_unlock_irqrestore(&emu->emu_lock, flags);
rate = 0x1770000 / (((value << 5) | value2)+1);
snd_iprintf(buffer, "SPDIF Locked : %d\n", rate);
} else {
@@ -410,14 +401,11 @@ static void snd_emu_proc_emu1010_reg_rea
{
struct snd_emu10k1 *emu = entry->private_data;
u32 value;
- unsigned long flags;
int i;
snd_iprintf(buffer, "EMU1010 Registers:\n\n");
for(i = 0; i < 0x40; i+=1) {
- spin_lock_irqsave(&emu->emu_lock, flags);
snd_emu1010_fpga_read(emu, i, &value);
- spin_unlock_irqrestore(&emu->emu_lock, flags);
snd_iprintf(buffer, "%02X: %08X, %02X\n", i, value, (value >> 8) & 0x7f);
}
}
Patches currently in stable-queue which might be from michael@xxxxxxxxxxx are
queue-3.10/alsa-emu10k1-don-t-deadlock-in-proc-functions.patch
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