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authorMichael Gernoth <michael@gernoth.net>2015-04-09 23:42:15 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-06 21:56:23 +0200
commit6c6f8aac03406e6cba87267a6075b4e3340af892 (patch)
tree5f6b1582bb2912f36cfd3c601f1ec54bddf06b39 /sound/pci
parente217fcc13682beef6eaafbb5a419e6b50ddf94b9 (diff)
downloadlinux-linaro-stable-6c6f8aac03406e6cba87267a6075b4e3340af892.tar.gz
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>
Diffstat (limited to 'sound/pci')
-rw-r--r--sound/pci/emu10k1/emuproc.c12
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);
}
}