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. Tested on Skystar S2. Changes respect override_or option so should still work fine on cx88 based cards which disable dynamic current limit. Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> Signed-off-by: Jemma Denson <jdenson@xxxxxxxxx> --- drivers/media/dvb-frontends/isl6421.c | 77 +++++++++++++++++++++++++++++++++-- 1 file changed, 73 insertions(+), 4 deletions(-) diff --git a/drivers/media/dvb-frontends/isl6421.c b/drivers/media/dvb-frontends/isl6421.c index 838b42771a05..f58590fe71f5 100644 --- a/drivers/media/dvb-frontends/isl6421.c +++ b/drivers/media/dvb-frontends/isl6421.c @@ -38,35 +38,102 @@ 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: return -EINVAL; } + /* + * 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_DCL; + isl6421->config |= isl6421->override_or; isl6421->config &= isl6421->override_and; - return (i2c_transfer(isl6421->i2c, &msg, 1) == 1) ? 0 : -EIO; + ret = i2c_transfer(isl6421->i2c, msg, 2); + if (ret < 0) + return ret; + if (ret != 2) + return -EIO; + + /* Store off status now incase future commands fail */ + isl6421->is_off = is_off; + + /* On overflow, the device will try again after 900 ms (typically) */ + if (!(isl6421->config & ISL6421_DCL) && (buf & ISL6421_OLF1)) + msleep(1000); + + /* Re-enable dynamic current limit after a certain amount of time */ + if ((isl6421->config & ISL6421_DCL) && + !(isl6421->override_or & ISL6421_DCL)) { + msleep(200); + isl6421->config &= ~ISL6421_DCL; + + ret = i2c_transfer(isl6421->i2c, msg, 2); + if (ret < 0) + return ret; + if (ret != 2) + return -EIO; + } + + /* Check if overload flag is active. If so, disable power */ + if (!is_off && (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 +215,8 @@ 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; -- 2.13.4
