Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932402AbcJ3WkZ (ORCPT ); Sun, 30 Oct 2016 18:40:25 -0400 Received: from ns.gsystem.sk ([62.176.172.50]:57889 "EHLO gsystem.sk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754544AbcJ3WkV (ORCPT ); Sun, 30 Oct 2016 18:40:21 -0400 From: Ondrej Zary To: Christoph Hellwig Cc: Finn Thain , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] g_NCR5380: Test the IRQ before accepting it Date: Sun, 30 Oct 2016 23:40:02 +0100 Message-Id: <1477867203-7480-2-git-send-email-linux@rainbow-software.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1477867203-7480-1-git-send-email-linux@rainbow-software.org> References: <1477867203-7480-1-git-send-email-linux@rainbow-software.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2009 Lines: 64 Trigger an IRQ first with a test IRQ handler to find out if it really works. Disable the IRQ if not. This prevents hang when incorrect IRQ was specified by user. Signed-off-by: Ondrej Zary --- drivers/scsi/g_NCR5380.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c index 3790ed5..261e168 100644 --- a/drivers/scsi/g_NCR5380.c +++ b/drivers/scsi/g_NCR5380.c @@ -67,6 +67,14 @@ MODULE_ALIAS("g_NCR5380_mmio"); MODULE_LICENSE("GPL"); +static bool irq_working; + +static irqreturn_t test_irq(int irq, void *dev_id) +{ + irq_working = true; + return IRQ_HANDLED; +} + /* * Configure I/O address of 53C400A or DTC436 by writing magic numbers * to ports 0x779 and 0x379. @@ -275,10 +283,30 @@ static int generic_NCR5380_init_one(struct scsi_host_template *tpnt, /* set IRQ for HP C2502 */ if (board == BOARD_HP_C2502) magic_configure(port_idx, instance->irq, magic); - if (request_irq(instance->irq, generic_NCR5380_intr, - 0, "NCR5380", instance)) { + /* test if the IRQ is working */ + irq_working = false; + if (request_irq(instance->irq, test_irq, + 0, "NCR5380-irqtest", NULL)) { printk(KERN_WARNING "scsi%d : IRQ%d not free, interrupts disabled\n", instance->host_no, instance->irq); instance->irq = NO_IRQ; + } else { + NCR5380_trigger_irq(instance); + NCR5380_read(RESET_PARITY_INTERRUPT_REG); + free_irq(instance->irq, NULL); + if (irq_working) { + if (request_irq(instance->irq, + generic_NCR5380_intr, 0, + "NCR5380", instance)) { + printk(KERN_WARNING "scsi%d : IRQ%d not free, interrupts disabled\n", + instance->host_no, + instance->irq); + instance->irq = NO_IRQ; + } + } else { + printk(KERN_WARNING "scsi%d : IRQ%d not working, interrupts disabled\n", + instance->host_no, instance->irq); + instance->irq = NO_IRQ; + } } } -- Ondrej Zary