Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756358Ab3EaMHL (ORCPT ); Fri, 31 May 2013 08:07:11 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:40029 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755644Ab3EaMGw (ORCPT ); Fri, 31 May 2013 08:06:52 -0400 Message-ID: <51A89258.7050308@ti.com> Date: Fri, 31 May 2013 07:06:48 -0500 From: Dan Murphy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: Oleksandr Dmytryshyn CC: Tony Lindgren , Wolfram Sang , , , Subject: Re: [PATCH v3 1/1] i2c: omap: correct usage of the interrupt enable register References: <1369988788-23987-1-git-send-email-oleksandr.dmytryshyn@ti.com> <1369988788-23987-2-git-send-email-oleksandr.dmytryshyn@ti.com> In-Reply-To: <1369988788-23987-2-git-send-email-oleksandr.dmytryshyn@ti.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3398 Lines: 93 On 05/31/2013 03:26 AM, Oleksandr Dmytryshyn wrote: > If the i2c controller during suspend will generate an interrupt, it > can lead to unpredictable behaviour in the kernel. > > Based on the logic of the kernel code interrupts from i2c should be > prohibited during suspend. Kernel writes 0 to the I2C_IE register in > the omap_i2c_runtime_suspend() function. In the other side kernel > writes saved interrupt flags to the I2C_IE register in > omap_i2c_runtime_resume() function. I.e. interrupts should be disabled > during suspend. > > This works for chips with version1 registers scheme. Interrupts are > disabled during suspend. For chips with version2 scheme registers > writting 0 to the I2C_IE register does nothing (because now the > I2C_IRQENABLE_SET register is located at this address). This register > is used to enable interrupts. For disabling interrupts > I2C_IRQENABLE_CLR register should be used. > > Because the registers I2C_IRQENABLE_SET and I2C_IE have the same > addresses, the interrupt enabling procedure is unchanged. > > Change-Id: Ie49165990a4e7c67a4ccf2e4a66cd3b78f2e2b70 Remove this. > Signed-off-by: Oleksandr Dmytryshyn > --- > drivers/i2c/busses/i2c-omap.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index e02f9e3..64c26f9 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -180,6 +180,8 @@ enum { > #define I2C_OMAP_ERRATA_I207 (1 << 0) > #define I2C_OMAP_ERRATA_I462 (1 << 1) > > +#define OMAP_I2C_IP_V2_INTERRUPTS_MASK 0x6FFF > + > struct omap_i2c_dev { > spinlock_t lock; /* IRQ synchronization */ > struct device *dev; > @@ -193,6 +195,7 @@ struct omap_i2c_dev { > long latency); > u32 speed; /* Speed of bus in kHz */ > u32 flags; > + u16 scheme; > u16 cmd_err; > u8 *buf; > u8 *regs; > @@ -1082,7 +1085,7 @@ omap_i2c_probe(struct platform_device *pdev) > int irq; > int r; > u32 rev; > - u16 minor, major, scheme; > + u16 minor, major; > > /* NOTE: driver uses the static register mapping */ > mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > @@ -1159,8 +1162,8 @@ omap_i2c_probe(struct platform_device *pdev) > */ > rev = __raw_readw(dev->base + 0x04); > > - scheme = OMAP_I2C_SCHEME(rev); > - switch (scheme) { > + dev->scheme = OMAP_I2C_SCHEME(rev); > + switch (dev->scheme) { > case OMAP_I2C_SCHEME_0: > dev->regs = (u8 *)reg_map_ip_v1; > dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG); > @@ -1289,7 +1292,11 @@ static int omap_i2c_runtime_suspend(struct device *dev) > > _dev->iestate = omap_i2c_read_reg(_dev, OMAP_I2C_IE_REG); > > - omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, 0); > + if (_dev->scheme == OMAP_I2C_SCHEME_0) > + omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, 0); > + else > + omap_i2c_write_reg(_dev, OMAP_I2C_IP_V2_IRQENABLE_CLR, > + OMAP_I2C_IP_V2_INTERRUPTS_MASK); > > if (_dev->rev < OMAP_I2C_OMAP1_REV_2) { > omap_i2c_read_reg(_dev, OMAP_I2C_IV_REG); /* Read clears */ -- ------------------ Dan Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/