V4L/DVB: dib3000mc: 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/dib3000mc.c:853: warning: the frame size of 2224 bytes is larger than 2048 bytes

and in 'make checkstack', the stack usage goes from:
0x00000bbd dib3000mc_i2c_enumeration [dib3000mc]:	2232
to unlisted with this patch.

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>
Acked-by: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Randy Dunlap 2010-02-08 20:30:33 -03:00 committed by Mauro Carvalho Chehab
parent 0b42760a75
commit 0de8e3533e

View File

@ -814,42 +814,51 @@ EXPORT_SYMBOL(dib3000mc_set_config);
int dib3000mc_i2c_enumeration(struct i2c_adapter *i2c, int no_of_demods, u8 default_addr, struct dib3000mc_config cfg[])
{
struct dib3000mc_state st = { .i2c_adap = i2c };
struct dib3000mc_state *dmcst;
int k;
u8 new_addr;
static u8 DIB3000MC_I2C_ADDRESS[] = {20,22,24,26};
dmcst = kzalloc(sizeof(struct dib3000mc_state), GFP_KERNEL);
if (dmcst == NULL)
return -ENODEV;
dmcst->i2c_adap = i2c;
for (k = no_of_demods-1; k >= 0; k--) {
st.cfg = &cfg[k];
dmcst->cfg = &cfg[k];
/* designated i2c address */
new_addr = DIB3000MC_I2C_ADDRESS[k];
st.i2c_addr = new_addr;
if (dib3000mc_identify(&st) != 0) {
st.i2c_addr = default_addr;
if (dib3000mc_identify(&st) != 0) {
dmcst->i2c_addr = new_addr;
if (dib3000mc_identify(dmcst) != 0) {
dmcst->i2c_addr = default_addr;
if (dib3000mc_identify(dmcst) != 0) {
dprintk("-E- DiB3000P/MC #%d: not identified\n", k);
kfree(dmcst);
return -ENODEV;
}
}
dib3000mc_set_output_mode(&st, OUTMODE_MPEG2_PAR_CONT_CLK);
dib3000mc_set_output_mode(dmcst, OUTMODE_MPEG2_PAR_CONT_CLK);
// set new i2c address and force divstr (Bit 1) to value 0 (Bit 0)
dib3000mc_write_word(&st, 1024, (new_addr << 3) | 0x1);
st.i2c_addr = new_addr;
dib3000mc_write_word(dmcst, 1024, (new_addr << 3) | 0x1);
dmcst->i2c_addr = new_addr;
}
for (k = 0; k < no_of_demods; k++) {
st.cfg = &cfg[k];
st.i2c_addr = DIB3000MC_I2C_ADDRESS[k];
dmcst->cfg = &cfg[k];
dmcst->i2c_addr = DIB3000MC_I2C_ADDRESS[k];
dib3000mc_write_word(&st, 1024, st.i2c_addr << 3);
dib3000mc_write_word(dmcst, 1024, dmcst->i2c_addr << 3);
/* turn off data output */
dib3000mc_set_output_mode(&st, OUTMODE_HIGH_Z);
dib3000mc_set_output_mode(dmcst, OUTMODE_HIGH_Z);
}
kfree(dmcst);
return 0;
}
EXPORT_SYMBOL(dib3000mc_i2c_enumeration);