Em Tue, 15 Aug 2017 20:51:09 +0100 Jemma Denson <jdenson@xxxxxxxxx> escreveu: > Hi Mauro, > > On 13/08/17 20:35, Mauro Carvalho Chehab wrote: > > > This Kaffeine's BZ: > > https://bugs.kde.org/show_bug.cgi?id=374693 > > > > affects SkyStar S2 PCI DVB-S/S2 rev 3.3 device. It could be due to > > a Kernel bug. > > > > While checking the Isil 6421, comparing with its manual, available at: > > > > http://www.intersil.com/content/dam/Intersil/documents/isl6/isl6421a.pdf > > > > It was noticed that, if the output load is highly capacitive, a different approach > > is recomended when energizing the LNBf. > > > > Also, it is possible to detect if a current overload is happening, by checking an > > special flag. > > > > Add support for it. > > > > Compile-tested only. > > > > Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> > > --- > > drivers/media/dvb-frontends/isl6421.c | 72 +++++++++++++++++++++++++++++++++-- > > 1 file changed, 68 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/media/dvb-frontends/isl6421.c b/drivers/media/dvb-frontends/isl6421.c > > index 838b42771a05..b04d56ad4ce8 100644 > > --- a/drivers/media/dvb-frontends/isl6421.c > > +++ b/drivers/media/dvb-frontends/isl6421.c > > @@ -38,25 +38,43 @@ struct isl6421 { > > u8 override_and; > > struct i2c_adapter *i2c; > > u8 i2c_addr; > > + bool is_off; > > }; > > > > static int isl6421_set_voltage(struct dvb_frontend *fe, > > enum fe_sec_voltage voltage) > > { > > + int ret; > > + u8 buf; > > + bool is_off; > > struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv; > > - struct i2c_msg msg = { .addr = isl6421->i2c_addr, .flags = 0, > > - .buf = &isl6421->config, > > - .len = sizeof(isl6421->config) }; > > + struct i2c_msg msg[2] = { > > + { > > + .addr = isl6421->i2c_addr, > > + .flags = 0, > > + .buf = &isl6421->config, > > + .len = 1, > > + }, { > > + .addr = isl6421->i2c_addr, > > + .flags = I2C_M_RD, > > + .buf = &buf, > > + .len = 1, > > + } > > + > > + }; > > > > isl6421->config &= ~(ISL6421_VSEL1 | ISL6421_EN1); > > > > switch(voltage) { > > case SEC_VOLTAGE_OFF: > > + is_off = true; > > break; > > case SEC_VOLTAGE_13: > > + is_off = false; > > isl6421->config |= ISL6421_EN1; > > break; > > case SEC_VOLTAGE_18: > > + is_off = false; > > isl6421->config |= (ISL6421_EN1 | ISL6421_VSEL1); > > break; > > default: > > @@ -66,7 +84,51 @@ static int isl6421_set_voltage(struct dvb_frontend *fe, > > isl6421->config |= isl6421->override_or; > > isl6421->config &= isl6421->override_and; > > > > - return (i2c_transfer(isl6421->i2c, &msg, 1) == 1) ? 0 : -EIO; > > + /* > > + * If LNBf were not powered on, disable dynamic current limit, as, > > + * according with datasheet, highly capacitive load on the output may > > + * cause a difficult start-up. > > + */ > > + if (isl6421->is_off && !is_off) > > + isl6421->config |= ISL6421_EN1; > > Checking the datasheet I think we need to be setting DCL high instead. EN1 is > already set anyway. Yes, that was the idea. Not sure what happened here :-) > > + > > + ret = i2c_transfer(isl6421->i2c, msg, 2); > > + if (ret < 0) > > + return ret; > > + if (ret != 2) > > + return -EIO; > > + > > + isl6421->is_off = is_off; > > Is this in the right place? On my first internal versions, this used to be below, but I guess the best is to place it here, because, if the next i2c_transfer fail, this would still reflect the current state. > > > + > > + /* On overflow, the device will try again after 900 ms (typically) */ > > + if (isl6421->is_off && (buf & ISL6421_OLF1)) > > + msleep(1000); > > 1000ms does only cover one cycle of OFF then ON - the device will keep cycling > 900ms off then 20ms on until overflow is cleared so it might take longer but > adding the code to support longer is probably not worth it. Waiting one cycle > is better than the current none anyway. Yes, I know it could wait for more time here, but not sure if it would be worth doing it. The problem is that 1000ms is already a lot of time, and if this gets too long, userspace may any giving up of tuning, anyway. > > + > > + if (isl6421->is_off && !is_off) { > > + isl6421->config &= ~ISL6421_EN1; Again, this should be DCL. > > + > > + ret = i2c_transfer(isl6421->i2c, msg, 2); > > + if (ret < 0) > > + return ret; > > + if (ret != 2) > > + return -EIO; > > + } > > Does this if statement ever match? isl6421->is_off and is_off are the same value > at this point. I presume this is supposed to be re-enabling DCL so would again > also need that bit instead of EN1. We might also need a little delay before > turning it on - the datasheet mentions a "chosen amount of time". I've no idea > what's appropriate here, 200ms? > > A simpler if statement might be just (isl6421->config & ISL6421_DCL), we just > need to check DCL was set high above. It used to, on my original version, where I was setting config->is_off only at the end :-) Yeah, checking for DCL is a way more reliable. > > > + > > + /* Check if overload flag is active. If so, disable power */ > > + if (buf & ISL6421_OLF1) { > > + isl6421->config &= ~(ISL6421_VSEL1 | ISL6421_EN1); > > + ret = i2c_transfer(isl6421->i2c, msg, 1); > > + if (ret < 0) > > + return ret; > > + if (ret != 1) > > + return -EIO; > > + isl6421->is_off = true; > > + > > + dev_warn(&isl6421->i2c->dev, > > + "Overload current detected. disabling LNBf power\n"); > > + return -EINVAL; > > + } > > + return 0; > > } > > > > static int isl6421_enable_high_lnb_voltage(struct dvb_frontend *fe, long arg) > > @@ -148,6 +210,8 @@ struct dvb_frontend *isl6421_attach(struct dvb_frontend *fe, struct i2c_adapter > > return NULL; > > } > > > > + isl6421->is_off = true; > > + > > /* install release callback */ > > fe->ops.release_sec = isl6421_release; > > > > I've just tested both your v2 patch and changes I'm suggesting above; both work > fine on my setup. Do you want me to send a v3? Yeah, sure! I'm currently in travel, returning only on Friday, and I don't have the hardware to test. So, if you can send it, I'd appreciate :-) Cheers, Mauro
