From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: [PATCH 09/09] sata_mv cache main_irq_mask register in hpriv Date: Sat, 17 May 2008 13:38:00 -0400 Message-ID: <482F17F8.3010403@rtr.ca> References: <482AE694.5080604@rtr.ca> <482AE6E2.4080900@rtr.ca> <482AE767.8090103@rtr.ca> <482AE817.2020809@rtr.ca> <482F1732.6010109@rtr.ca> <482F1759.20905@rtr.ca> <482F179E.8020602@rtr.ca> <482F17C3.8020106@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rtr.ca ([76.10.145.34]:2708 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753991AbYEQRiB (ORCPT ); Sat, 17 May 2008 13:38:01 -0400 In-Reply-To: <482F17C3.8020106@rtr.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik , Tejun Heo Cc: Alan Cox , IDE/ATA development list Part five of simplifying/fixing handling of the main_irq_mask register to resolve unexpected interrupt issues observed in 2.6.26-rc*. Keep a cached copy of the main_irq_mask so that we don't have to stall the CPU to read it on every pass through mv_interrupt. This significantly speeds up interrupt handling, both for sata_mv, and for any other driver/device sharing the same PCI IRQ line. Signed-off-by: Mark Lord --- old/drivers/ata/sata_mv.c 2008-05-16 16:06:23.000000000 -0400 +++ linux/drivers/ata/sata_mv.c 2008-05-16 16:02:55.000000000 -0400 @@ -458,6 +458,7 @@ struct mv_host_priv { u32 hp_flags; + u32 main_irq_mask; struct mv_port_signal signal[8]; const struct mv_hw_ops *ops; int n_ports; @@ -843,10 +844,12 @@ struct mv_host_priv *hpriv = host->private_data; u32 old_mask, new_mask; - old_mask = readl(hpriv->main_irq_mask_addr); + old_mask = hpriv->main_irq_mask; new_mask = (old_mask & ~disable_bits) | enable_bits; - if (new_mask != old_mask) + if (new_mask != old_mask) { + hpriv->main_irq_mask = new_mask; writelfl(new_mask, hpriv->main_irq_mask_addr); + } } static void mv_enable_port_irqs(struct ata_port *ap, @@ -2200,12 +2203,11 @@ struct ata_host *host = dev_instance; struct mv_host_priv *hpriv = host->private_data; unsigned int handled = 0; - u32 main_irq_cause, main_irq_mask, pending_irqs; + u32 main_irq_cause, pending_irqs; spin_lock(&host->lock); main_irq_cause = readl(hpriv->main_irq_cause_addr); - main_irq_mask = readl(hpriv->main_irq_mask_addr); - pending_irqs = main_irq_cause & main_irq_mask; + pending_irqs = main_irq_cause & hpriv->main_irq_mask; /* * Deal with cases where we either have nothing pending, or have read * a bogus register value which can indicate HW removal or PCI fault.