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i2c: designware: fix IO timeout issue for AMD controller

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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@amd.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
This commit is contained in:
Xiangliang Yu 2015-12-11 20:02:53 +08:00 committed by Wolfram Sang
parent 5212f9ae51
commit 2d244c8148
3 changed files with 13 additions and 1 deletions
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6
drivers/i2c/busses/i2c-designware-core.c
View File

@ -813,6 +813,12 @@ static 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;
}

1
drivers/i2c/busses/i2c-designware-core.h
View File

@ -111,6 +111,7 @@ struct dw_i2c_dev {
#define ACCESS_SWAP 0x00000001
#define ACCESS_16BIT 0x00000002
#define ACCESS_INTR_MASK 0x00000004
extern int i2c_dw_init(struct dw_i2c_dev *dev);
extern void i2c_dw_disable(struct dw_i2c_dev *dev);

7
drivers/i2c/busses/i2c-designware-platdrv.c
View File

@ -93,6 +93,7 @@ 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;
@ -106,6 +107,10 @@ 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;
}
@ -116,7 +121,7 @@ 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);