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Commit d39f77b0 authored by Andrew Jackson's avatar Andrew Jackson Committed by Wolfram Sang
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i2c: designware: prevent early stop on TX FIFO empty 



If the Designware core is configured with IC_EMPTYFIFO_HOLD_MASTER_EN
set to zero, allowing the TX FIFO to become empty causes a STOP
condition to be generated on the I2C bus. If the transmit FIFO
threshold is set too high, an erroneous STOP condition can be
generated on long transfers - particularly where the interrupt
latency is extended.

Signed-off-by: default avatarAndrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: default avatarLiviu Dudau <Liviu.Dudau@arm.com>
Tested-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 27caca9d

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

+1 −1
Original line number Diff line number Diff line
@@ -359,7 +359,7 @@ int i2c_dw_init(struct dw_i2c_dev *dev) 
	}



	/* Configure Tx/Rx FIFO threshold levels */

	dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL);

	dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);

	dw_writel(dev, 0, DW_IC_RX_TL);



	/* configure the i2c master */