Commit 09d87466 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

media: atomisp: reduce the risk of a race condition 



This driver is really on bad shape. One of the problems
is that, as soon as the I2C transfers start to happen, it
timeouts detecting a camera:

	ov2680 i2c-OVTI2680:00: ov2680_probe: ACPI detected it on bus ID=CAM1, HID=OVTI2680
	atomisp-isp2 0000:00:03.0: no camera attached or fail to detect
	ov2680 i2c-OVTI2680:00: gmin: initializing atomisp module subdev data using PMIC regulator
	...

The right fix here would be to use defer probe, but driver is
still on too bad shape.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent d03f2e24

drivers/staging/media/atomisp/pci/atomisp_v4l2.c

+23 −2
Original line number Diff line number Diff line
@@ -46,6 +46,10 @@ 


#include "device_access.h"



/* Timeouts to wait for all subdevs to be registered */

#define SUBDEV_WAIT_TIMEOUT		50 /* ms */

#define SUBDEV_WAIT_TIMEOUT_MAX_COUNT	40 /* up to 2 seconds */



/* G-Min addition: pull this in from intel_mid_pm.h */

#define CSTATE_EXIT_LATENCY_C1  1
@@ -1082,7 +1086,7 @@ static int atomisp_subdev_probe(struct atomisp_device *isp) 
{

	const struct atomisp_platform_data *pdata;

	struct intel_v4l2_subdev_table *subdevs;

	int ret, raw_index = -1;

	int ret, raw_index = -1, count;



	pdata = atomisp_get_platform_data();

	if (!pdata) {
@@ -1090,6 +1094,8 @@ static int atomisp_subdev_probe(struct atomisp_device *isp) 
		return 0;

	}



	/* FIXME: should, instead, use I2C probe */



	for (subdevs = pdata->subdevs; subdevs->type; ++subdevs) {

		struct v4l2_subdev *subdev;

		struct i2c_board_info *board_info =
@@ -1098,6 +1104,8 @@ static int atomisp_subdev_probe(struct atomisp_device *isp) 
		    i2c_get_adapter(subdevs->v4l2_subdev.i2c_adapter_id);

		int sensor_num, i;



		dev_info(isp->dev, "Probing Subdev %s\n", board_info->type);



		if (!adapter) {

			dev_err(isp->dev,

				"Failed to find i2c adapter for subdev %s\n",
@@ -1177,6 +1185,16 @@ static int atomisp_subdev_probe(struct atomisp_device *isp) 
		}

	}



	/* FIXME: should return -EPROBE_DEFER if not all subdevs were probed */

	for (count = 0; count < SUBDEV_WAIT_TIMEOUT_MAX_COUNT; count++) {

		if (isp->input_cnt)

			break;

		msleep(SUBDEV_WAIT_TIMEOUT);

		count++;

	}

	/* Wait more time to give more time for subdev init code */

	msleep(5 * SUBDEV_WAIT_TIMEOUT);



	/*

	 * HACK: Currently VCM belongs to primary sensor only, but correct

	 * approach must be to acquire from platform code which sensor
@@ -1186,8 +1204,11 @@ static int atomisp_subdev_probe(struct atomisp_device *isp) 
		isp->inputs[raw_index].motor = isp->motor;



	/* Proceed even if no modules detected. For COS mode and no modules. */

	if (!isp->inputs[0].camera)

	if (!isp->input_cnt)

		dev_warn(isp->dev, "no camera attached or fail to detect\n");

	else

		dev_info(isp->dev, "detected %d camera sensors\n",

			 isp->input_cnt);



	return atomisp_csi_lane_config(isp);

}

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