Messages in this thread | | | Subject | Re: [media] duplicate code in media drivers | From | "Gustavo A. R. Silva" <> | Date | Tue, 22 May 2018 11:36:21 -0500 |
| |
Mauro,
I already sent some patches based on your comments.
Thanks! -- Gustavo
On 05/21/2018 03:14 PM, Mauro Carvalho Chehab wrote: > Em Mon, 21 May 2018 14:39:51 -0500 > "Gustavo A. R. Silva" <gustavo@embeddedor.com> escreveu: > >> Hi Mauro, >> >> I found some duplicate code with the help of Coccinelle and Coverity. Notice that these are not code patches, they only point out the duplicate code in some media drivers: >> >> diff -u -p drivers/media/pci/bt8xx/dvb-bt8xx.c /tmp/nothing/media/pci/bt8xx/dvb-bt8xx.c >> --- drivers/media/pci/bt8xx/dvb-bt8xx.c >> +++ /tmp/nothing/media/pci/bt8xx/dvb-bt8xx.c >> @@ -389,9 +389,7 @@ static int advbt771_samsung_tdtc9251dh0_ >> else if (c->frequency < 600000000) >> bs = 0x08; >> else if (c->frequency < 730000000) >> - bs = 0x08; >> else >> - bs = 0x08; >> >> pllbuf[0] = 0x61; >> pllbuf[1] = div >> 8; > > > Hmm... I *suspect* that "bs" here controls the frequency range for the > tuner. Analog tuners have separate frequency regions that are controlled > via a register, into a 4 or 5 bytes I2C sequence. They're all somewhat > a clone of an old Philips design. > > It should be safe to convert the "BS" sequence on something like: > > if (c->frequency < 173000000) > bs = 0x01; > else if (c->frequency < 470000000) > bs = 0x02; > else > bs = 0x08; > > > >> diff -u -p drivers/media/usb/dvb-usb/dib0700_devices.c /tmp/nothing/media/usb/dvb-usb/dib0700_devices.c >> --- drivers/media/usb/dvb-usb/dib0700_devices.c >> +++ /tmp/nothing/media/usb/dvb-usb/dib0700_devices.c >> @@ -1741,13 +1741,6 @@ static int dib809x_tuner_attach(struct d >> struct dib0700_adapter_state *st = adap->priv; >> struct i2c_adapter *tun_i2c = st->dib8000_ops.get_i2c_master(adap->fe_adap[0].fe, DIBX000_I2C_INTERFACE_TUNER, 1); >> >> - if (adap->id == 0) { >> - if (dvb_attach(dib0090_register, adap->fe_adap[0].fe, tun_i2c, &dib809x_dib0090_config) == NULL) >> - return -ENODEV; >> - } else { >> - if (dvb_attach(dib0090_register, adap->fe_adap[0].fe, tun_i2c, &dib809x_dib0090_config) == NULL) >> - return -ENODEV; >> - } > > I'm almost sure that, on the second if, it should be adap->fe_adap[1].fe. > I tried in the past to check this, but didn't got an answer from the one > that wrote the code. > > Maybe we could add a /* FIXME: check if it is fe_adap[1] */ on the > second clause. > >> >> st->set_param_save = adap->fe_adap[0].fe->ops.tuner_ops.set_params; >> adap->fe_adap[0].fe->ops.tuner_ops.set_params = dib8096_set_param_override; >> diff -u -p drivers/media/dvb-frontends/mb86a16.c /tmp/nothing/media/dvb-frontends/mb86a16.c >> --- drivers/media/dvb-frontends/mb86a16.c >> +++ /tmp/nothing/media/dvb-frontends/mb86a16.c >> @@ -1466,9 +1466,7 @@ static int mb86a16_set_fe(struct mb86a16 >> wait_t = (1572864 + state->srate / 2) / state->srate; >> if (state->srate < 5000) >> /* FIXME ! , should be a long wait ! */ >> - msleep_interruptible(wait_t); >> else >> - msleep_interruptible(wait_t); > > I suspect that the goal here is to point that sleeping for > (1572864 + state->srate / 2) / state->srate when srate is low will mean > that it will take a lot of time to converge (probably causing timeout at > userspace). > > Basically, if srate is < 5000, the sleep time will be between > 314 and 1575364 ms. The worse case scenario - although not realistic, > in practice - is to wait up to 26 seconds. This is a very long time! > > Probably, the right fix here would be to check if wait_t is bigger than > a certain amount of time. If so, return an error. > > I'm not against removing the if, but, if so, better to add a /* FIXME */ > block explaining that. > > That's said, this is an old device. I doubt anyone would fix it. > > >> >> if (sync_chk(state, &junk) == 0) { >> iq_vt_set(state, 1); >> diff -u -p drivers/media/dvb-frontends/au8522_decoder.c /tmp/nothing/media/dvb-frontends/au8522_decoder.c >> --- drivers/media/dvb-frontends/au8522_decoder.c >> +++ /tmp/nothing/media/dvb-frontends/au8522_decoder.c >> @@ -280,14 +280,9 @@ static void setup_decoder_defaults(struc >> AU8522_TOREGAAGC_REG0E5H_CVBS); >> au8522_writereg(state, AU8522_REG016H, AU8522_REG016H_CVBS); >> >> - if (is_svideo) { >> /* Despite what the table says, for the HVR-950q we still need >> to be in CVBS mode for the S-Video input (reason unknown). */ >> /* filter_coef_type = 3; */ >> - filter_coef_type = 5; >> - } else { >> - filter_coef_type = 5; >> - } > > Better ask Devin about this (c/c). > >> >> /* Load the Video Decoder Filter Coefficients */ >> for (i = 0; i < NUM_FILTER_COEF; i++) { >> >> >> I wonder if some of the cases above were intentionally coded that way or some code needs to be removed. >> >> Thanks >> -- >> Gustavo > > > > Thanks, > Mauro >
| |