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Commit cef777c9 authored by Tejas Prajapati's avatar Tejas Prajapati
Browse files

msm: camera: reqmgr: reader writer locks to avoid memory faults 



Shared memory is initialized by CRM and used by
other drivers; with CRM not active other drivers
would fail to access the shared memory if
memory manager is deinit. Reader Writer locks can
prevent the open/close/ioctl calls from other drivers
if CRM open/close is already being processed.

Issue observed with the below sequence if drivers
are opened from UMD directly without this change.
CRM Open successful,ICP open successful,
CRM close in progress, ICP open successful,
mem mgr deinit and CRM close successful,
ICP tries to access HFI memory and result in crash.

This change helps to serialze the calls and prevents
issue.

CRs-Fixed: 3019488
Change-Id: Ifdf198c2e3593050573c66aeba69d50d131435b9
Signed-off-by: default avatarTejas Prajapati <quic_tpraja@quicinc.com>
parent 0b4ab69a

drivers/cam_core/cam_subdev.c

+2 −0
Original line number Diff line number Diff line
@@ -53,8 +53,10 @@ static long cam_subdev_ioctl(struct v4l2_subdev *sd, unsigned int cmd, 


	switch (cmd) {

	case VIDIOC_CAM_CONTROL:

		cam_req_mgr_rwsem_read_op(CAM_SUBDEV_LOCK);

		rc = cam_node_handle_ioctl(node,

			(struct cam_control *) arg);

		cam_req_mgr_rwsem_read_op(CAM_SUBDEV_UNLOCK);

		break;

	default:

		CAM_ERR(CAM_CORE, "Invalid command %d for %s", cmd,

drivers/cam_fd/cam_fd_dev.c

+5 −0
Original line number Diff line number Diff line
@@ -43,8 +43,11 @@ static int cam_fd_dev_open(struct v4l2_subdev *sd, 
{

	struct cam_fd_dev *fd_dev = &g_fd_dev;



	cam_req_mgr_rwsem_read_op(CAM_SUBDEV_LOCK);



	if (!fd_dev->probe_done) {

		CAM_ERR(CAM_FD, "FD Dev not initialized, fd_dev=%pK", fd_dev);

		cam_req_mgr_rwsem_read_op(CAM_SUBDEV_UNLOCK);

		return -ENODEV;

	}
@@ -53,6 +56,8 @@ static int cam_fd_dev_open(struct v4l2_subdev *sd, 
	CAM_DBG(CAM_FD, "FD Subdev open count %d", fd_dev->open_cnt);

	mutex_unlock(&fd_dev->lock);



	cam_req_mgr_rwsem_read_op(CAM_SUBDEV_UNLOCK);



	return 0;

}

drivers/cam_icp/cam_icp_subdev.c

+3 −0
Original line number Diff line number Diff line
@@ -75,6 +75,8 @@ static int cam_icp_subdev_open(struct v4l2_subdev *sd, 
	struct cam_node *node = v4l2_get_subdevdata(sd);

	int rc = 0;



	cam_req_mgr_rwsem_read_op(CAM_SUBDEV_LOCK);



	mutex_lock(&g_icp_dev.icp_lock);

	if (g_icp_dev.open_cnt >= 1) {

		CAM_ERR(CAM_ICP, "ICP subdev is already opened");
@@ -97,6 +99,7 @@ static int cam_icp_subdev_open(struct v4l2_subdev *sd, 
	g_icp_dev.open_cnt++;

end:

	mutex_unlock(&g_icp_dev.icp_lock);

	cam_req_mgr_rwsem_read_op(CAM_SUBDEV_UNLOCK);

	return rc;

}

drivers/cam_isp/cam_isp_dev.c

+4 −0
Original line number Diff line number Diff line
@@ -50,10 +50,14 @@ static const struct of_device_id cam_isp_dt_match[] = { 
static int cam_isp_subdev_open(struct v4l2_subdev *sd,

	struct v4l2_subdev_fh *fh)

{

	cam_req_mgr_rwsem_read_op(CAM_SUBDEV_LOCK);



	mutex_lock(&g_isp_dev.isp_mutex);

	g_isp_dev.open_cnt++;

	mutex_unlock(&g_isp_dev.isp_mutex);



	cam_req_mgr_rwsem_read_op(CAM_SUBDEV_UNLOCK);



	return 0;

}

drivers/cam_jpeg/cam_jpeg_dev.c

+2 −0
Original line number Diff line number Diff line
@@ -49,10 +49,12 @@ static const struct of_device_id cam_jpeg_dt_match[] = { 
static int cam_jpeg_subdev_open(struct v4l2_subdev *sd,

	struct v4l2_subdev_fh *fh)

{

	cam_req_mgr_rwsem_read_op(CAM_SUBDEV_LOCK);



	mutex_lock(&g_jpeg_dev.jpeg_mutex);

	g_jpeg_dev.open_cnt++;

	mutex_unlock(&g_jpeg_dev.jpeg_mutex);

	cam_req_mgr_rwsem_read_op(CAM_SUBDEV_UNLOCK);



	return 0;

}