From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756875Ab3BEXLo (ORCPT ); Tue, 5 Feb 2013 18:11:44 -0500 Received: from mail-pa0-f43.google.com ([209.85.220.43]:64275 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756604Ab3BEXKw (ORCPT ); Tue, 5 Feb 2013 18:10:52 -0500 From: Girish K S To: spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Subject: [PATCH 1/4] spi: s3c64xx: modified error interrupt handling and init Date: Tue, 5 Feb 2013 15:09:41 -0800 Message-Id: <1360105784-12282-2-git-send-email-ks.giri@samsung.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1360105784-12282-1-git-send-email-ks.giri@samsung.com> References: <1360105784-12282-1-git-send-email-ks.giri@samsung.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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); 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); writel(0, regs + S3C64XX_SPI_SWAP_CFG); -- 1.7.10.4