Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753995AbbEBTOM (ORCPT ); Sat, 2 May 2015 15:14:12 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44644 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752684AbbEBTOH (ORCPT ); Sat, 2 May 2015 15:14:07 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Gernoth , Takashi Iwai Subject: [PATCH 4.0 091/220] ALSA: emu10k1: dont deadlock in proc-functions Date: Sat, 2 May 2015 21:00:06 +0200 Message-Id: <20150502185858.279448683@linuxfoundation.org> X-Mailer: git-send-email 2.3.7 In-Reply-To: <20150502185854.333748961@linuxfoundation.org> References: <20150502185854.333748961@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2853 Lines: 81 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Gernoth 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: Greg Kroah-Hartman --- 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); } } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/