Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 32ec4576 authored by Dan Carpenter's avatar Dan Carpenter Committed by Mauro Carvalho Chehab
Browse files

V4L/DVB: media/az6027: doing dma on the stack 

I changed the dma buffers to use allocated memory instead of stack
memory.

The reason for this is documented in Documentation/DMA-API-HOWTO.txt
under the section:  "What memory is DMA'able?"  That document was only
added a couple weeks ago and there are still lots of modules which
haven't been corrected yet.  Btw. Smatch includes a pretty good test to
find places which use stack memory as a dma buffer.  That's how I found
these.  (http://smatch.sf.net

).

Signed-off-by: default avatarDan Carpenter <error27@gmail.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 9723dbb0

drivers/media/dvb/dvb-usb/az6027.c

+41 −9
Original line number Diff line number Diff line
@@ -417,11 +417,15 @@ static int az6027_ci_read_attribute_mem(struct dvb_ca_en50221 *ca, 
	u16 value;

	u16 index;

	int blen;

	u8 b[12];

	u8 *b;



	if (slot != 0)

		return -EINVAL;



	b = kmalloc(12, GFP_KERNEL);

	if (!b)

		return -ENOMEM;



	mutex_lock(&state->ca_mutex);



	req = 0xC1;
@@ -438,6 +442,7 @@ static int az6027_ci_read_attribute_mem(struct dvb_ca_en50221 *ca, 
	}



	mutex_unlock(&state->ca_mutex);

	kfree(b);

	return ret;

}
@@ -485,11 +490,15 @@ static int az6027_ci_read_cam_control(struct dvb_ca_en50221 *ca, 
	u16 value;

	u16 index;

	int blen;

	u8 b[12];

	u8 *b;



	if (slot != 0)

		return -EINVAL;



	b = kmalloc(12, GFP_KERNEL);

	if (!b)

		return -ENOMEM;



	mutex_lock(&state->ca_mutex);



	req = 0xC3;
@@ -510,6 +519,7 @@ static int az6027_ci_read_cam_control(struct dvb_ca_en50221 *ca, 
	}



	mutex_unlock(&state->ca_mutex);

	kfree(b);

	return ret;

}
@@ -556,7 +566,11 @@ static int CI_CamReady(struct dvb_ca_en50221 *ca, int slot) 
	u16 value;

	u16 index;

	int blen;

	u8 b[12];

	u8 *b;



	b = kmalloc(12, GFP_KERNEL);

	if (!b)

		return -ENOMEM;



	req = 0xC8;

	value = 0;
@@ -570,6 +584,7 @@ static int CI_CamReady(struct dvb_ca_en50221 *ca, int slot) 
	} else{

		ret = b[0];

	}

	kfree(b);

	return ret;

}
@@ -667,8 +682,11 @@ static int az6027_ci_poll_slot_status(struct dvb_ca_en50221 *ca, int slot, int o 
	u16 value;

	u16 index;

	int blen;

	u8 b[12];

	u8 *b;



	b = kmalloc(12, GFP_KERNEL);

	if (!b)

		return -ENOMEM;

	mutex_lock(&state->ca_mutex);



	req = 0xC5;
@@ -692,6 +710,7 @@ static int az6027_ci_poll_slot_status(struct dvb_ca_en50221 *ca, int slot, int o 
	}



	mutex_unlock(&state->ca_mutex);

	kfree(b);

	return ret;

}
@@ -943,10 +962,16 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n 
	u16 value;

	int length;

	u8 req;

	u8 data[256];

	u8 *data;



	data = kmalloc(256, GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	if (mutex_lock_interruptible(&d->i2c_mutex) < 0)

	if (mutex_lock_interruptible(&d->i2c_mutex) < 0) {

		kfree(data);

		return -EAGAIN;

	}



	if (num > 2)

		warn("more than 2 i2c messages at a time is not handled yet. TODO.");
@@ -1016,6 +1041,7 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n 
		}

	}

	mutex_unlock(&d->i2c_mutex);

	kfree(data);



	return i;

}
@@ -1036,8 +1062,14 @@ int az6027_identify_state(struct usb_device *udev, 
			  struct dvb_usb_device_description **desc,

			  int *cold)

{

	u8 b[16];

	s16 ret = usb_control_msg(udev,

	u8 *b;

	s16 ret;



	b = kmalloc(16, GFP_KERNEL);

	if (!b)

		return -ENOMEM;



	ret = usb_control_msg(udev,

				  usb_rcvctrlpipe(udev, 0),

				  0xb7,

				  USB_TYPE_VENDOR | USB_DIR_IN,
@@ -1048,7 +1080,7 @@ int az6027_identify_state(struct usb_device *udev, 
				  USB_CTRL_GET_TIMEOUT);



	*cold = ret <= 0;



	kfree(b);

	deb_info("cold: %d\n", *cold);

	return 0;

}