4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Xiangliang Yu <Xiangliang.Yu@xxxxxxx> commit 2d244c81481fa5142a2ba6656ab7a8e40c849c27 upstream. Because of some hardware limitation, AMD I2C controller can't trigger pending interrupt if interrupt status has been changed after clearing interrupt status bits. Then, I2C will lost interrupt and IO timeout. According to hardware design, this patch implements a workaround to disable i2c controller interrupt and re-enable i2c interrupt before exiting ISR. To reduce the performance impacts on other vendors, use unlikely function to check flag in ISR. Signed-off-by: Xiangliang Yu <Xiangliang.Yu@xxxxxxx> Acked-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx> Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx> Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx> --- drivers/i2c/busses/i2c-designware-core.c | 6 ++++++ drivers/i2c/busses/i2c-designware-core.h | 1 + drivers/i2c/busses/i2c-designware-platdrv.c | 7 ++++++- 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 6f19a33..75b1ffd 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -811,6 +811,12 @@ irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) tx_aborted: if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err) complete(&dev->cmd_complete); + else if (unlikely(dev->accessor_flags & ACCESS_INTR_MASK)) { + /* workaround to trigger pending interrupt */ + stat = dw_readl(dev, DW_IC_INTR_MASK); + i2c_dw_disable_int(dev); + dw_writel(dev, stat, DW_IC_INTR_MASK); + } return IRQ_HANDLED; } diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 9630222..808ef6a 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -111,6 +111,7 @@ struct dw_i2c_dev { #define ACCESS_SWAP 0x00000001 #define ACCESS_16BIT 0x00000002 +#define ACCESS_INTR_MASK 0x00000004 extern u32 dw_readl(struct dw_i2c_dev *dev, int offset); extern void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset); diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 4bf5fc1..13a7f10 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -97,6 +97,7 @@ static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], static int dw_i2c_acpi_configure(struct platform_device *pdev) { struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + const struct acpi_device_id *id; dev->adapter.nr = -1; dev->tx_fifo_depth = 32; @@ -110,6 +111,10 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev) dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &dev->sda_hold_time); + id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); + if (id && id->driver_data) + dev->accessor_flags |= (u32)id->driver_data; + return 0; } @@ -120,7 +125,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = { { "INT3433", 0 }, { "80860F41", 0 }, { "808622C1", 0 }, - { "AMD0010", 0 }, + { "AMD0010", ACCESS_INTR_MASK }, { } }; MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html