Commit 2d244c81 authored by Xiangliang Yu's avatar Xiangliang Yu Committed by Wolfram Sang
Browse files

i2c: designware: fix IO timeout issue for AMD controller 



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: default avatarXiangliang Yu <Xiangliang.Yu@amd.com>
Acked-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
parent 5212f9ae

drivers/i2c/busses/i2c-designware-core.c

+6 −0
Original line number Diff line number Diff line
@@ -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;

}

drivers/i2c/busses/i2c-designware-core.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

drivers/i2c/busses/i2c-designware-platdrv.c

+6 −1
Original line number Diff line number Diff line
@@ -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);

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