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Subject[PATCH 07/16] [media] friio: get rid of on-stack dma buffers
Date
usb_control_msg initiates (and waits for completion of) a dma transfer using
the supplied buffer. That buffer thus has to be seperately allocated on
the heap.

In lib/dma_debug.c the function check_for_stack even warns about it:
WARNING: at lib/dma-debug.c:866 check_for_stack

Note: This change is tested to compile only, as I don't have the hardware.

Signed-off-by: Florian Mickler <florian@mickler.org>
---
drivers/media/dvb/dvb-usb/friio.c | 23 +++++++++++++++++++----
1 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/media/dvb/dvb-usb/friio.c b/drivers/media/dvb/dvb-usb/friio.c
index 14a65b4..76159ae 100644
--- a/drivers/media/dvb/dvb-usb/friio.c
+++ b/drivers/media/dvb/dvb-usb/friio.c
@@ -142,17 +142,20 @@ static u32 gl861_i2c_func(struct i2c_adapter *adapter)
return I2C_FUNC_I2C;
}

-
static int friio_ext_ctl(struct dvb_usb_adapter *adap,
u32 sat_color, int lnb_on)
{
int i;
int ret;
struct i2c_msg msg;
- u8 buf[2];
+ u8 *buf;
u32 mask;
u8 lnb = (lnb_on) ? FRIIO_CTL_LNB : 0;

+ buf = kmalloc(2, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
msg.addr = 0x00;
msg.flags = 0;
msg.len = 2;
@@ -189,6 +192,7 @@ static int friio_ext_ctl(struct dvb_usb_adapter *adap,
buf[1] |= FRIIO_CTL_CLK;
ret += gl861_i2c_xfer(&adap->dev->i2c_adap, &msg, 1);

+ kfree(buf);
return (ret == 70);
}

@@ -219,11 +223,20 @@ static int friio_initialize(struct dvb_usb_device *d)
int ret;
int i;
int retry = 0;
- u8 rbuf[2];
- u8 wbuf[3];
+ u8 *rbuf, *wbuf;

deb_info("%s called.\n", __func__);

+ wbuf = kmalloc(3, GFP_KERNEL);
+ if (!wbuf)
+ return -ENOMEM;
+
+ rbuf = kmalloc(2, GFP_KERNEL);
+ if (!rbuf) {
+ kfree(wbuf);
+ return -ENOMEM;
+ }
+
/* use gl861_i2c_msg instead of gl861_i2c_xfer(), */
/* because the i2c device is not set up yet. */
wbuf[0] = 0x11;
@@ -358,6 +371,8 @@ restart:
return 0;

error:
+ kfree(wbuf);
+ kfree(rbuf);
deb_info("%s:ret == %d\n", __func__, ret);
return -EIO;
}
--
1.7.4.rc3


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