diff mbox series

[v5,1/3] i2c: imx: Fix reset of I2SR_IAL flag

Message ID 20201007084524.10835-2-ceggers@arri.de
State Superseded
Headers show
Series i2c: imx: Fix handling of arbitration loss | expand

Commit Message

Christian Eggers Oct. 7, 2020, 8:45 a.m. UTC 
According to the "VFxxx Controller Reference Manual" (and the comment
block starting at line 97), Vybrid requires writing a one for clearing
an interrupt flag. Syncing the method for clearing I2SR_IIF in
i2c_imx_isr().

Signed-off-by: Christian Eggers <ceggers@arri.de>
Fixes: 4b775022f6fd ("i2c: imx: add struct to hold more configurable quirks")
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable@vger.kernel.org
---
 drivers/i2c/busses/i2c-imx.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

Comments

Wolfram Sang Oct. 8, 2020, 9:56 a.m. UTC | #1 
On Wed, Oct 07, 2020 at 10:45:22AM +0200, Christian Eggers wrote:
> According to the "VFxxx Controller Reference Manual" (and the comment
> block starting at line 97), Vybrid requires writing a one for clearing
> an interrupt flag. Syncing the method for clearing I2SR_IIF in
> i2c_imx_isr().
> 
> Signed-off-by: Christian Eggers <ceggers@arri.de>
> Fixes: 4b775022f6fd ("i2c: imx: add struct to hold more configurable quirks")
> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Cc: stable@vger.kernel.org

Applied to for-current, thanks!

Waiting for review tags for patches 2 & 3.
Oleksij Rempel Oct. 9, 2020, 7:11 a.m. UTC | #2 
Hi Christian,

On Wed, Oct 07, 2020 at 10:45:22AM +0200, Christian Eggers wrote:
> According to the "VFxxx Controller Reference Manual" (and the comment
> block starting at line 97), Vybrid requires writing a one for clearing
> an interrupt flag. Syncing the method for clearing I2SR_IIF in
> i2c_imx_isr().
> 
> Signed-off-by: Christian Eggers <ceggers@arri.de>
> Fixes: 4b775022f6fd ("i2c: imx: add struct to hold more configurable quirks")
> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Cc: stable@vger.kernel.org
> ---
>  drivers/i2c/busses/i2c-imx.c | 20 +++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index 0ab5381aa012..cbdcab73a055 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -412,6 +412,19 @@ static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
>  	dma->chan_using = NULL;
>  }
>  
> +static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits)
> +{
> +	unsigned int temp;
> +
> +	/*
> +	 * i2sr_clr_opcode is the value to clear all interrupts. Here we want to
> +	 * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits>
> +	 * toggled. This is required because i.MX needs W1C and Vybrid uses W0C.
> +	 */

This comment need correction. The i.MX needs W0C and Vybrid uses W1C 

> +	temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits;
> +	imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
> +}
> +
>  static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)
>  {
>  	unsigned long orig_jiffies = jiffies;
> @@ -424,8 +437,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a
>  
>  		/* check for arbitration lost */
>  		if (temp & I2SR_IAL) {
> -			temp &= ~I2SR_IAL;
> -			imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
> +			i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
>  			return -EAGAIN;
>  		}
>  
> @@ -623,9 +635,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
>  	if (temp & I2SR_IIF) {
>  		/* save status register */
>  		i2c_imx->i2csr = temp;
> -		temp &= ~I2SR_IIF;
> -		temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);
> -		imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
> +		i2c_imx_clear_irq(i2c_imx, I2SR_IIF);
>  		wake_up(&i2c_imx->queue);
>  		return IRQ_HANDLED;
>  	}
> -- 

Otherwise

Acked-by: Oleksij Rempel <o.rempel@pengutronix.de> 

Regards,
Oleksij
Oleksij Rempel Oct. 9, 2020, 7:52 a.m. UTC | #3 
On Fri, Oct 09, 2020 at 09:11:32AM +0200, Oleksij Rempel wrote:
> Hi Christian,
> 
> On Wed, Oct 07, 2020 at 10:45:22AM +0200, Christian Eggers wrote:
> > According to the "VFxxx Controller Reference Manual" (and the comment
> > block starting at line 97), Vybrid requires writing a one for clearing
> > an interrupt flag. Syncing the method for clearing I2SR_IIF in
> > i2c_imx_isr().
> > 
> > Signed-off-by: Christian Eggers <ceggers@arri.de>
> > Fixes: 4b775022f6fd ("i2c: imx: add struct to hold more configurable quirks")
> > Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > Cc: stable@vger.kernel.org
> > ---
> >  drivers/i2c/busses/i2c-imx.c | 20 +++++++++++++++-----
> >  1 file changed, 15 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> > index 0ab5381aa012..cbdcab73a055 100644
> > --- a/drivers/i2c/busses/i2c-imx.c
> > +++ b/drivers/i2c/busses/i2c-imx.c
> > @@ -412,6 +412,19 @@ static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
> >  	dma->chan_using = NULL;
> >  }
> >  
> > +static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits)
> > +{
> > +	unsigned int temp;
> > +
> > +	/*
> > +	 * i2sr_clr_opcode is the value to clear all interrupts. Here we want to
> > +	 * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits>
> > +	 * toggled. This is required because i.MX needs W1C and Vybrid uses W0C.
> > +	 */
> 
> This comment need correction. The i.MX needs W0C and Vybrid uses W1C 
> 
> > +	temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits;
> > +	imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
> > +}
> > +
> >  static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)
> >  {
> >  	unsigned long orig_jiffies = jiffies;
> > @@ -424,8 +437,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a
> >  
> >  		/* check for arbitration lost */
> >  		if (temp & I2SR_IAL) {
> > -			temp &= ~I2SR_IAL;
> > -			imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
> > +			i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
> >  			return -EAGAIN;
> >  		}
> >  
> > @@ -623,9 +635,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
> >  	if (temp & I2SR_IIF) {
> >  		/* save status register */
> >  		i2c_imx->i2csr = temp;
> > -		temp &= ~I2SR_IIF;
> > -		temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);
> > -		imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
> > +		i2c_imx_clear_irq(i2c_imx, I2SR_IIF);
> >  		wake_up(&i2c_imx->queue);
> >  		return IRQ_HANDLED;
> >  	}
> > -- 
> 
> Otherwise
> 
> Acked-by: Oleksij Rempel <o.rempel@pengutronix.de> 

By reviewing the second patch we found at least one more missing Vybrid
related case in the i2c_imx_trx_complete() function:
	imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);

	this is OK for iMX by broken on Vybrid.

Since you already fixing it in this patch for some of IMX_I2C_I2SR
writes, please do it here as well. This is the last unhandled case...:)

Regards,
Oleksij
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 0ab5381aa012..cbdcab73a055 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -412,6 +412,19 @@  static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
 	dma->chan_using = NULL;
 }
 
+static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits)
+{
+	unsigned int temp;
+
+	/*
+	 * i2sr_clr_opcode is the value to clear all interrupts. Here we want to
+	 * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits>
+	 * toggled. This is required because i.MX needs W1C and Vybrid uses W0C.
+	 */
+	temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits;
+	imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
+}
+
 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)
 {
 	unsigned long orig_jiffies = jiffies;
@@ -424,8 +437,7 @@  static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a
 
 		/* check for arbitration lost */
 		if (temp & I2SR_IAL) {
-			temp &= ~I2SR_IAL;
-			imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
+			i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
 			return -EAGAIN;
 		}
 
@@ -623,9 +635,7 @@  static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 	if (temp & I2SR_IIF) {
 		/* save status register */
 		i2c_imx->i2csr = temp;
-		temp &= ~I2SR_IIF;
-		temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);
-		imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
+		i2c_imx_clear_irq(i2c_imx, I2SR_IIF);
 		wake_up(&i2c_imx->queue);
 		return IRQ_HANDLED;
 	}