diff options
| author | Michael Gernoth <michael@gernoth.net> | 2015-04-09 23:42:15 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-05-06 21:56:23 +0200 |
| commit | 6c6f8aac03406e6cba87267a6075b4e3340af892 (patch) | |
| tree | 5f6b1582bb2912f36cfd3c601f1ec54bddf06b39 | |
| parent | e217fcc13682beef6eaafbb5a419e6b50ddf94b9 (diff) | |
ALSA: emu10k1: don't deadlock in proc-functions
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@gernoth.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | sound/pci/emu10k1/emuproc.c | 12 |
1 files changed, 0 insertions, 12 deletions
diff --git a/sound/pci/emu10k1/emuproc.c b/sound/pci/emu10k1/emuproc.c index 2ca9f2e93139..53745f4c2bf5 100644 --- 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_info_entry *entry, 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_read(struct snd_info_entry *entry, { 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); } } |