From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH 1/4] spi: s3c64xx: modified error interrupt handling and init Date: Wed, 06 Feb 2013 10:26:28 +0000 Message-ID: <20130206102628.5E7413E1510@localhost> References: <1360105784-12282-1-git-send-email-ks.giri@samsung.com> <1360105784-12282-2-git-send-email-ks.giri@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Girish K S , spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: In-Reply-To: <1360105784-12282-2-git-send-email-ks.giri-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On Tue, 5 Feb 2013 15:09:41 -0800, Girish K S wrote: > The status of the interrupt is available in the status register, > so reading the clear pending register and writing back the same > value will not actually clear the pending interrupts. This patch > modifies the interrupt handler to read the status register and > clear the corresponding pending bit in the clear pending register. > > Modified the hwInit function to clear all the pending interrupts. > > Signed-off-by: Girish K S > --- > drivers/spi/spi-s3c64xx.c | 41 +++++++++++++++++++++++++---------------- > 1 file changed, 25 insertions(+), 16 deletions(-) > > diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c > index ad93231..b770f88 100644 > --- a/drivers/spi/spi-s3c64xx.c > +++ b/drivers/spi/spi-s3c64xx.c > @@ -997,25 +997,30 @@ static irqreturn_t s3c64xx_spi_irq(int irq, void *data) > { > struct s3c64xx_spi_driver_data *sdd = data; > struct spi_master *spi = sdd->master; > - unsigned int val; > + unsigned int val, clr = 0; > > - val = readl(sdd->regs + S3C64XX_SPI_PENDING_CLR); > + val = readl(sdd->regs + S3C64XX_SPI_STATUS); > > - val &= S3C64XX_SPI_PND_RX_OVERRUN_CLR | > - S3C64XX_SPI_PND_RX_UNDERRUN_CLR | > - S3C64XX_SPI_PND_TX_OVERRUN_CLR | > - S3C64XX_SPI_PND_TX_UNDERRUN_CLR; > - > - writel(val, sdd->regs + S3C64XX_SPI_PENDING_CLR); > - > - if (val & S3C64XX_SPI_PND_RX_OVERRUN_CLR) > + if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) { > + clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR; > dev_err(&spi->dev, "RX overrun\n"); > - if (val & S3C64XX_SPI_PND_RX_UNDERRUN_CLR) > + } > + if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) { > + clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR; > dev_err(&spi->dev, "RX underrun\n"); > - if (val & S3C64XX_SPI_PND_TX_OVERRUN_CLR) > + } > + if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) { > + clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR; > dev_err(&spi->dev, "TX overrun\n"); > - if (val & S3C64XX_SPI_PND_TX_UNDERRUN_CLR) > + } > + if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) { > + clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR; > dev_err(&spi->dev, "TX underrun\n"); > + } > + > + /* Clear the pending irq by setting and then clearing it */ > + writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR); > + writel(clr & ~clr, sdd->regs + S3C64XX_SPI_PENDING_CLR); Wait, what? clr & ~clr == 0 Always. What are you actually trying to do here? > > return IRQ_HANDLED; > } > @@ -1039,9 +1044,13 @@ static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel) > writel(0, regs + S3C64XX_SPI_MODE_CFG); > writel(0, regs + S3C64XX_SPI_PACKET_CNT); > > - /* Clear any irq pending bits */ > - writel(readl(regs + S3C64XX_SPI_PENDING_CLR), > - regs + S3C64XX_SPI_PENDING_CLR); > + /* Clear any irq pending bits, should set and clear the bits */ > + val = S3C64XX_SPI_PND_RX_OVERRUN_CLR | > + S3C64XX_SPI_PND_RX_UNDERRUN_CLR | > + S3C64XX_SPI_PND_TX_OVERRUN_CLR | > + S3C64XX_SPI_PND_TX_UNDERRUN_CLR; > + writel(val, regs + S3C64XX_SPI_PENDING_CLR); > + writel(val & ~val, regs + S3C64XX_SPI_PENDING_CLR); Ditto. g. ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb