Commit 49839dc9 authored by Paul Walmsley's avatar Paul Walmsley Committed by Wolfram Sang
Browse files

Revert "ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints" 

This reverts commit 3db11fef
(ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints).
This commit causes I2C timeouts to appear on several OMAP3430/3530-based
boards:

  http://marc.info/?l=linux-arm-kernel&m=135071372426971&w=2
  http://marc.info/?l=linux-arm-kernel&m=135067558415214&w=2
  http://marc.info/?l=linux-arm-kernel&m=135216013608196&w=2

and appears to have been sent for merging before one of its prerequisites
was merged:

  http://marc.info/?l=linux-arm-kernel&m=135219411617621&w=2



Signed-off-by: default avatarPaul Walmsley <paul@pwsan.com>
Acked-by: default avatarJean Pihet <j-pihet@ti.com>
Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent 7c3fe64d

arch/arm/plat-omap/i2c.c

+21 −0
Original line number Diff line number Diff line
@@ -26,12 +26,14 @@ 
#include <linux/kernel.h>

#include <linux/platform_device.h>

#include <linux/i2c.h>

#include <linux/i2c-omap.h>

#include <linux/slab.h>

#include <linux/err.h>

#include <linux/clk.h>



#include <mach/irqs.h>

#include <plat/i2c.h>

#include <plat/omap-pm.h>

#include <plat/omap_device.h>



#define OMAP_I2C_SIZE		0x3f
@@ -127,6 +129,16 @@ static inline int omap1_i2c_add_bus(int bus_id) 




#ifdef CONFIG_ARCH_OMAP2PLUS

/*

 * XXX This function is a temporary compatibility wrapper - only

 * needed until the I2C driver can be converted to call

 * omap_pm_set_max_dev_wakeup_lat() and handle a return code.

 */

static void omap_pm_set_max_mpu_wakeup_lat_compat(struct device *dev, long t)

{

	omap_pm_set_max_mpu_wakeup_lat(dev, t);

}



static inline int omap2_i2c_add_bus(int bus_id)

{

	int l;
@@ -158,6 +170,15 @@ static inline int omap2_i2c_add_bus(int bus_id) 
	dev_attr = (struct omap_i2c_dev_attr *)oh->dev_attr;

	pdata->flags = dev_attr->flags;



	/*

	 * When waiting for completion of a i2c transfer, we need to

	 * set a wake up latency constraint for the MPU. This is to

	 * ensure quick enough wakeup from idle, when transfer

	 * completes.

	 * Only omap3 has support for constraints

	 */

	if (cpu_is_omap34xx())

		pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat;

	pdev = omap_device_build(name, bus_id, oh, pdata,

			sizeof(struct omap_i2c_bus_platform_data),

			NULL, 0, 0);

drivers/i2c/busses/i2c-omap.c

+14 −18
Original line number Diff line number Diff line
@@ -43,7 +43,6 @@ 
#include <linux/slab.h>

#include <linux/i2c-omap.h>

#include <linux/pm_runtime.h>

#include <linux/pm_qos.h>



/* I2C controller revisions */

#define OMAP_I2C_OMAP1_REV_2		0x20
@@ -187,8 +186,9 @@ struct omap_i2c_dev { 
	int			reg_shift;      /* bit shift for I2C register addresses */

	struct completion	cmd_complete;

	struct resource		*ioarea;

	u32			latency;	/* maximum MPU wkup latency */

	struct pm_qos_request	pm_qos_request;

	u32			latency;	/* maximum mpu wkup latency */

	void			(*set_mpu_wkup_lat)(struct device *dev,

						    long latency);

	u32			speed;		/* Speed of bus in kHz */

	u32			dtrev;		/* extra revision from DT */

	u32			flags;
@@ -494,7 +494,9 @@ static void omap_i2c_resize_fifo(struct omap_i2c_dev *dev, u8 size, bool is_rx) 
		dev->b_hw = 1; /* Enable hardware fixes */



	/* calculate wakeup latency constraint for MPU */

	dev->latency = (1000000 * dev->threshold) / (1000 * dev->speed / 8);

	if (dev->set_mpu_wkup_lat != NULL)

		dev->latency = (1000000 * dev->threshold) /

			(1000 * dev->speed / 8);

}



/*
@@ -629,16 +631,8 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
	if (r < 0)

		goto out;



	/*

	 * When waiting for completion of a i2c transfer, we need to

	 * set a wake up latency constraint for the MPU. This is to

	 * ensure quick enough wakeup from idle, when transfer

	 * completes.

	 */

	if (dev->latency)

		pm_qos_add_request(&dev->pm_qos_request,

				   PM_QOS_CPU_DMA_LATENCY,

				   dev->latency);

	if (dev->set_mpu_wkup_lat != NULL)

		dev->set_mpu_wkup_lat(dev->dev, dev->latency);



	for (i = 0; i < num; i++) {

		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
@@ -646,8 +640,8 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
			break;

	}



	if (dev->latency)

		pm_qos_remove_request(&dev->pm_qos_request);

	if (dev->set_mpu_wkup_lat != NULL)

		dev->set_mpu_wkup_lat(dev->dev, -1);



	if (r == 0)

		r = num;
@@ -1104,6 +1098,7 @@ omap_i2c_probe(struct platform_device *pdev) 
	} else if (pdata != NULL) {

		dev->speed = pdata->clkrate;

		dev->flags = pdata->flags;

		dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;

		dev->dtrev = pdata->rev;

	}
@@ -1159,6 +1154,7 @@ omap_i2c_probe(struct platform_device *pdev) 
			dev->b_hw = 1; /* Enable hardware fixes */



		/* calculate wakeup latency constraint for MPU */

		if (dev->set_mpu_wkup_lat != NULL)

			dev->latency = (1000000 * dev->fifo_size) /

				       (1000 * dev->speed / 8);

	}

include/linux/i2c-omap.h

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ struct omap_i2c_bus_platform_data { 
	u32		clkrate;

	u32		rev;

	u32		flags;

	void		(*set_mpu_wkup_lat)(struct device *dev, long set);

};



#endif

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