From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753573AbaIALFg (ORCPT ); Mon, 1 Sep 2014 07:05:36 -0400 Received: from mail.mev.co.uk ([62.49.15.74]:39050 "EHLO mail.mev.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753491AbaIALEf (ORCPT ); Mon, 1 Sep 2014 07:04:35 -0400 From: Ian Abbott To: driverdev-devel@linuxdriverproject.org Cc: Greg Kroah-Hartman , Ian Abbott , H Hartley Sweeten , linux-kernel@vger.kernel.org Subject: [PATCH 28/28] staging: comedi: amplc_pci230: simplify interrupt enable handling Date: Mon, 1 Sep 2014 12:04:00 +0100 Message-Id: <1409569440-10979-29-git-send-email-abbotti@mev.co.uk> X-Mailer: git-send-email 2.0.4 In-Reply-To: <1409569440-10979-1-git-send-email-abbotti@mev.co.uk> References: <1409569440-10979-1-git-send-email-abbotti@mev.co.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org `struct pci230_private` has two members to manage the enabled interrupt sources. `int_en` is the interrupt sources we want to be enabled and `ier` is a shadow of the write-only interrupt enable register. They have the same value most of the time. They differ in the interrupt handler (`pci230_interrupt()`) itself when it temporarily clears bits in the interrupt enable register and the `ier` member in order to unlatch them in hardware, but leaves the `int_en` member alone. They also differ in `pci230_ai_stop()` and `pci230_ao_stop()` which clear bits in the `int_en` member and wait for the interrupt handler to finish before copying the value to the `ier` member and the interrupt enable register. Simplify the handling a bit, by making the `ier` member take on the role of the `int_en` member, and allowing the value to differ from the interrupt enable register while the interrupt handler is running. Signed-off-by: Ian Abbott --- drivers/staging/comedi/drivers/amplc_pci230.c | 32 +++++++++------------------ 1 file changed, 10 insertions(+), 22 deletions(-) diff --git a/drivers/staging/comedi/drivers/amplc_pci230.c b/drivers/staging/comedi/drivers/amplc_pci230.c index 7748e17..66e7a47 100644 --- a/drivers/staging/comedi/drivers/amplc_pci230.c +++ b/drivers/staging/comedi/drivers/amplc_pci230.c @@ -499,8 +499,7 @@ struct pci230_private { unsigned short daccon; /* DACCON register value */ unsigned short adcfifothresh; /* ADC FIFO threshold (PCI230+/260+) */ unsigned short adcg; /* ADCG register value */ - unsigned char int_en; /* Interrupt enable bits */ - unsigned char ier; /* Copy of interrupt enable register */ + unsigned char ier; /* Interrupt enable bits */ unsigned char res_owned[NUM_OWNERS]; /* Owned resources */ bool intr_running:1; /* Flag set in interrupt routine */ bool ai_bipolar:1; /* Flag AI range is bipolar */ @@ -1049,15 +1048,12 @@ static void pci230_ao_stop(struct comedi_device *dev, * unless we are called from the interrupt routine. */ spin_lock_irqsave(&devpriv->isr_spinlock, irqflags); - devpriv->int_en &= ~intsrc; + devpriv->ier &= ~intsrc; while (devpriv->intr_running && devpriv->intr_cpuid != THISCPU) { spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); spin_lock_irqsave(&devpriv->isr_spinlock, irqflags); } - if (devpriv->ier != devpriv->int_en) { - devpriv->ier = devpriv->int_en; - outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); - } + outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); if (devpriv->hwver >= 2) { /* @@ -1311,7 +1307,6 @@ static void pci230_ao_start(struct comedi_device *dev, /* Not using DAC FIFO. */ /* Enable CT1 timer interrupt. */ spin_lock_irqsave(&devpriv->isr_spinlock, irqflags); - devpriv->int_en |= PCI230_INT_ZCLK_CT1; devpriv->ier |= PCI230_INT_ZCLK_CT1; outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); spin_unlock_irqrestore(&devpriv->isr_spinlock, @@ -1327,7 +1322,6 @@ static void pci230_ao_start(struct comedi_device *dev, if (devpriv->hwver >= 2) { /* Using DAC FIFO. Enable DAC FIFO interrupt. */ spin_lock_irqsave(&devpriv->isr_spinlock, irqflags); - devpriv->int_en |= PCI230P2_INT_DAC; devpriv->ier |= PCI230P2_INT_DAC; outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); @@ -1892,15 +1886,12 @@ static void pci230_ai_stop(struct comedi_device *dev, * Disable ADC interrupt and wait for interrupt routine to finish * running unless we are called from the interrupt routine. */ - devpriv->int_en &= ~PCI230_INT_ADC; + devpriv->ier &= ~PCI230_INT_ADC; while (devpriv->intr_running && devpriv->intr_cpuid != THISCPU) { spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); spin_lock_irqsave(&devpriv->isr_spinlock, irqflags); } - if (devpriv->ier != devpriv->int_en) { - devpriv->ier = devpriv->int_en; - outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); - } + outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); /* * Reset FIFO, disable FIFO and set start conversion source to none. @@ -1935,7 +1926,6 @@ static void pci230_ai_start(struct comedi_device *dev, /* Enable ADC FIFO trigger level interrupt. */ spin_lock_irqsave(&devpriv->isr_spinlock, irqflags); - devpriv->int_en |= PCI230_INT_ADC; devpriv->ier |= PCI230_INT_ADC; outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); @@ -2379,7 +2369,7 @@ static int pci230_ai_cancel(struct comedi_device *dev, /* Interrupt handler */ static irqreturn_t pci230_interrupt(int irq, void *d) { - unsigned char status_int, valid_status_int; + unsigned char status_int, valid_status_int, temp_ier; struct comedi_device *dev = (struct comedi_device *)d; struct pci230_private *devpriv = dev->private; struct comedi_subdevice *s; @@ -2392,14 +2382,14 @@ static irqreturn_t pci230_interrupt(int irq, void *d) return IRQ_NONE; spin_lock_irqsave(&devpriv->isr_spinlock, irqflags); - valid_status_int = devpriv->int_en & status_int; + valid_status_int = devpriv->ier & status_int; /* * Disable triggered interrupts. * (Only those interrupts that need re-enabling, are, later in the * handler). */ - devpriv->ier = devpriv->int_en & ~status_int; - outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); + temp_ier = devpriv->ier & ~status_int; + outb(temp_ier, dev->iobase + PCI230_INT_SCE); devpriv->intr_running = true; devpriv->intr_cpuid = THISCPU; spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); @@ -2432,10 +2422,8 @@ static irqreturn_t pci230_interrupt(int irq, void *d) /* Reenable interrupts. */ spin_lock_irqsave(&devpriv->isr_spinlock, irqflags); - if (devpriv->ier != devpriv->int_en) { - devpriv->ier = devpriv->int_en; + if (devpriv->ier != temp_ier) outb(devpriv->ier, dev->iobase + PCI230_INT_SCE); - } devpriv->intr_running = false; spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags); -- 2.0.4