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Commit e3c97650 authored by Baruch Siach's avatar Baruch Siach Committed by Wolfram Sang
Browse files

i2c: designware: remove redundant lock 



The per adapter bus_lock already projects from concurrent calls to the
master_xfer callback. No need to add a driver internal lock.

Also, rephrase a comment to drop mention of this lock.

Reported-by: default avatarRongrong Zou <zourongrong@gmail.com>
Signed-off-by: default avatarBaruch Siach <baruch@tkos.co.il>
Acked-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent f7418793

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

+6 −8
Original line number Diff line number Diff line
@@ -634,7 +634,6 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 


	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);



	mutex_lock(&dev->lock);

	pm_runtime_get_sync(dev->dev);



	reinit_completion(&dev->cmd_complete);
@@ -673,11 +672,12 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
	}



	/*

	 * We must disable the adapter before unlocking the &dev->lock mutex

	 * below. Otherwise the hardware might continue generating interrupts

	 * which in turn causes a race condition with the following transfer.

	 * Needs some more investigation if the additional interrupts are

	 * a hardware bug or this driver doesn't handle them correctly yet.

	 * We must disable the adapter before returning and signaling the end

	 * of the current transfer. Otherwise the hardware might continue

	 * generating interrupts which in turn causes a race condition with

	 * the following transfer.  Needs some more investigation if the

	 * additional interrupts are a hardware bug or this driver doesn't

	 * handle them correctly yet.

	 */

	__i2c_dw_enable(dev, false);
@@ -706,7 +706,6 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
done_nolock:

	pm_runtime_mark_last_busy(dev->dev);

	pm_runtime_put_autosuspend(dev->dev);

	mutex_unlock(&dev->lock);



	return ret;

}
@@ -860,7 +859,6 @@ int i2c_dw_probe(struct dw_i2c_dev *dev) 
	int r;



	init_completion(&dev->cmd_complete);

	mutex_init(&dev->lock);



	r = i2c_dw_init(dev);

	if (r)

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

+0 −2
Original line number Diff line number Diff line
@@ -36,7 +36,6 @@ 
 * @dev: driver model device node

 * @base: IO registers pointer

 * @cmd_complete: tx completion indicator

 * @lock: protect this struct and IO registers

 * @clk: input reference clock

 * @cmd_err: run time hadware error code

 * @msgs: points to an array of messages currently being transfered
@@ -73,7 +72,6 @@ struct dw_i2c_dev { 
	struct device		*dev;

	void __iomem		*base;

	struct completion	cmd_complete;

	struct mutex		lock;

	struct clk		*clk;

	u32			(*get_clk_rate_khz) (struct dw_i2c_dev *dev);

	struct dw_pci_controller *controller;