From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:51248 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752764AbbEDMiF (ORCPT ); Mon, 4 May 2015 08:38:05 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: Michael Gernoth , Takashi Iwai , Jiri Slaby Subject: [patch added to the 3.12 stable tree] ALSA: emu10k1: don't deadlock in proc-functions Date: Mon, 4 May 2015 14:37:19 +0200 Message-Id: <1430743082-6957-28-git-send-email-jslaby@suse.cz> In-Reply-To: <1430743082-6957-1-git-send-email-jslaby@suse.cz> References: <1430743082-6957-1-git-send-email-jslaby@suse.cz> Sender: stable-owner@vger.kernel.org List-ID: From: Michael Gernoth This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== 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 Signed-off-by: Takashi Iwai Signed-off-by: Jiri Slaby --- sound/pci/emu10k1/emuproc.c | 12 ------------ 1 file changed, 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); } } -- 2.3.5