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 Cc: stable@vger.kernel.org --- drivers/i2c/busses/i2c-imx.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 0ab5381aa012..34648df7f1a6 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -424,7 +424,12 @@ 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; + /* + * i2sr_clr_opcode is the value to clear all interrupts. + * Here we want to clear only I2SR_IAL, so we write + * ~i2sr_clr_opcode with just the I2SR_IAL bit toggled. + */ + temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ I2SR_IAL; imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); return -EAGAIN; } @@ -623,8 +628,12 @@ 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); + /* + * i2sr_clr_opcode is the value to clear all interrupts. + * Here we want to clear only I2SR_IIF, so we write + * ~i2sr_clr_opcode with just the I2SR_IIF bit toggled. + */ + temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ I2SR_IIF; imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); wake_up(&i2c_imx->queue); return IRQ_HANDLED;
On Fri, Oct 02, 2020 at 05:23:03PM +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 Cc: stable@vger.kernel.org
drivers/i2c/busses/i2c-imx.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
Tested (not extensively) on Vybrid VF500 (Toradex VF50): Tested-by: Krzysztof Kozlowski krzk@kernel.org
The I2C on Vybrid VF500 still works fine. I did not test this actual condition (arbitration) but only a regular I2C driver (BQ27xxx fuel gauge).
Best regards, Krzysztof
On Fri, Oct 02, 2020 at 05:23:03PM +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 Cc: stable@vger.kernel.org
drivers/i2c/busses/i2c-imx.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 0ab5381aa012..34648df7f1a6 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -424,7 +424,12 @@ 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;
/*
* i2sr_clr_opcode is the value to clear all interrupts.
* Here we want to clear only I2SR_IAL, so we write
* ~i2sr_clr_opcode with just the I2SR_IAL bit toggled.
*/
temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ I2SR_IAL; imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); return -EAGAIN;
Could we please move clearing an irq to a dedicated function? Such that it looks like:
/* check for arbitration lost */ if (temp & I2SR_IAL) { i2c_imx_clear_irq(i2c_imx, I2SR_IAL); return -EAGAIN; }
Then you also don't need to duplicate the describing comment but just add it to the implementation of i2c_imx_clear_irq().
Best regards Uwe
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