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V4L/DVB: dib7000p: reduce large stack usage 

This patch reduces static stack usage of one of the 2 top offenders
as listed by 'make checkstack':

Building with CONFIG_FRAME_WARN=2048 produces:

drivers/media/dvb/frontends/dib7000p.c:1367: warning: the frame size of 2320 bytes is larger than 2048 bytes

and in 'make checkstack', the stack usage goes from:
0x00002409 dib7000p_i2c_enumeration [dib7000p]:		2328
to unlisted with this patch.

Also change one caller of dib7000p_i2c_enumeration() to check its
return value.

I don't have the hardware that is needed to test this patch.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Randy Dunlap 2010-02-08 20:30:44 -03:00 committed by Mauro Carvalho Chehab
parent 84e2f037ce
commit 30d81bb086
2 changed files with 25 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/media/dvb/dvb-usb/cxusb.c
View File

@ -1025,8 +1025,9 @@ static int cxusb_dualdig4_rev2_frontend_attach(struct dvb_usb_adapter *adap)
cxusb_bluebird_gpio_pulse(adap->dev, 0x02, 1);
dib7000p_i2c_enumeration(&adap->dev->i2c_adap, 1, 18,
&cxusb_dualdig4_rev2_config);
if (dib7000p_i2c_enumeration(&adap->dev->i2c_adap, 1, 18,
&cxusb_dualdig4_rev2_config) < 0)
return -ENODEV;
adap->fe = dvb_attach(dib7000p_attach, &adap->dev->i2c_adap, 0x80,
&cxusb_dualdig4_rev2_config);

36
drivers/media/dvb/frontends/dib7000p.c
View File

@ -1324,46 +1324,54 @@ EXPORT_SYMBOL(dib7000p_pid_filter);
int dib7000p_i2c_enumeration(struct i2c_adapter *i2c, int no_of_demods, u8 default_addr, struct dib7000p_config cfg[])
{
struct dib7000p_state st = { .i2c_adap = i2c };
struct dib7000p_state *dpst;
int k = 0;
u8 new_addr = 0;
dpst = kzalloc(sizeof(struct dib7000p_state), GFP_KERNEL);
if (!dpst)
return -ENODEV;
dpst->i2c_adap = i2c;
for (k = no_of_demods-1; k >= 0; k--) {
st.cfg = cfg[k];
dpst->cfg = cfg[k];
/* designated i2c address */
new_addr = (0x40 + k) << 1;
st.i2c_addr = new_addr;
dib7000p_write_word(&st, 1287, 0x0003); /* sram lead in, rdy */
if (dib7000p_identify(&st) != 0) {
st.i2c_addr = default_addr;
dib7000p_write_word(&st, 1287, 0x0003); /* sram lead in, rdy */
if (dib7000p_identify(&st) != 0) {
dpst->i2c_addr = new_addr;
dib7000p_write_word(dpst, 1287, 0x0003); /* sram lead in, rdy */
if (dib7000p_identify(dpst) != 0) {
dpst->i2c_addr = default_addr;
dib7000p_write_word(dpst, 1287, 0x0003); /* sram lead in, rdy */
if (dib7000p_identify(dpst) != 0) {
dprintk("DiB7000P #%d: not identified\n", k);
kfree(dpst);
return -EIO;
}
}
/* start diversity to pull_down div_str - just for i2c-enumeration */
dib7000p_set_output_mode(&st, OUTMODE_DIVERSITY);
dib7000p_set_output_mode(dpst, OUTMODE_DIVERSITY);
/* set new i2c address and force divstart */
dib7000p_write_word(&st, 1285, (new_addr << 2) | 0x2);
dib7000p_write_word(dpst, 1285, (new_addr << 2) | 0x2);
dprintk("IC %d initialized (to i2c_address 0x%x)", k, new_addr);
}
for (k = 0; k < no_of_demods; k++) {
st.cfg = cfg[k];
st.i2c_addr = (0x40 + k) << 1;
dpst->cfg = cfg[k];
dpst->i2c_addr = (0x40 + k) << 1;
// unforce divstr
dib7000p_write_word(&st, 1285, st.i2c_addr << 2);
dib7000p_write_word(dpst, 1285, dpst->i2c_addr << 2);
/* deactivate div - it was just for i2c-enumeration */
dib7000p_set_output_mode(&st, OUTMODE_HIGH_Z);
dib7000p_set_output_mode(dpst, OUTMODE_HIGH_Z);
}
kfree(dpst);
return 0;
}
EXPORT_SYMBOL(dib7000p_i2c_enumeration);