This is a note to let you know that I've just added the patch titled

iio: adc: qcom-spmi-adc5: Initialize prescale properly

to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-next branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release during the merge window.

If you have any questions about this process, please let me know.

From db23d88756abd38e0995ea8449d0025b3de4b26b Mon Sep 17 00:00:00 2001

From: Evan Green evgreen@chromium.org Date: Tue, 4 Dec 2018 11:14:19 -0800 Subject: iio: adc: qcom-spmi-adc5: Initialize prescale properly

adc5_get_dt_data uses a local, prop, feeds it to adc5_get_dt_channel_data, and then puts the result into adc->chan_props. The problem is adc5_get_dt_channel_data may not initialize that structure fully, so a garbage value is used for prescale if the optional "qcom,pre-scaling" is not defined in DT. adc5_read_raw then uses this as an array index, generating a crash that looks like this:

[ 6.683186] Unable to handle kernel paging request at virtual address ffffff90e78c7964 Call trace: qcom_vadc_scale_code_voltage_factor+0x74/0x104 qcom_vadc_scale_hw_calib_die_temp+0x20/0x60 qcom_adc5_hw_scale+0x78/0xa4 adc5_read_raw+0x3d0/0x65c iio_channel_read+0x240/0x30c iio_read_channel_processed+0x10c/0x150 qpnp_tm_get_temp+0xc0/0x40c of_thermal_get_temp+0x7c/0x98 thermal_zone_get_temp+0xac/0xd8 thermal_zone_device_update+0xc0/0x38c qpnp_tm_probe+0x624/0x81c platform_drv_probe+0xe4/0x11c really_probe+0x188/0x3fc driver_probe_device+0xb8/0x188 __device_attach_driver+0x114/0x180 bus_for_each_drv+0xd8/0x118 __device_attach+0x180/0x27c device_initial_probe+0x20/0x2c bus_probe_device+0x78/0x124 deferred_probe_work_func+0xfc/0x138 process_one_work+0x3d8/0x8b0 process_scheduled_works+0x48/0x6c worker_thread+0x488/0x7cc kthread+0x24c/0x264 ret_from_fork+0x10/0x18

Unfortunately, when I went to add the initializer for this and tried to boot it, my machine shut down immediately, complaining that it was hotter than the sun. It appears that adc5_chans_pmic and adc5_chans_rev2 were initializing prescale_index as if it were directly a divisor, rather than the index into adc5_prescale_ratios that it is.

Fix the uninitialized value, and change the static initialization to use indices into adc5_prescale_ratios.

Signed-off-by: Evan Green evgreen@chromium.org Reviewed-by: Matthias Kaehlcke mka@chromium.org Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- drivers/iio/adc/qcom-spmi-adc5.c | 58 +++++++++++++++++--------------- 1 file changed, 31 insertions(+), 27 deletions(-)

diff --git a/drivers/iio/adc/qcom-spmi-adc5.c b/drivers/iio/adc/qcom-spmi-adc5.c index f9af6b082916..6a866cc187f7 100644 --- a/drivers/iio/adc/qcom-spmi-adc5.c +++ b/drivers/iio/adc/qcom-spmi-adc5.c @@ -423,6 +423,7 @@ struct adc5_channels { enum vadc_scale_fn_type scale_fn_type; };

+/* In these definitions, _pre refers to an index into adc5_prescale_ratios. */ #define ADC5_CHAN(_dname, _type, _mask, _pre, _scale) \ { \ .datasheet_name = _dname, \ @@ -443,63 +444,63 @@ struct adc5_channels { _pre, _scale) \

static const struct adc5_channels adc5_chans_pmic[ADC5_MAX_CHANNEL] = { - [ADC5_REF_GND] = ADC5_CHAN_VOLT("ref_gnd", 1, + [ADC5_REF_GND] = ADC5_CHAN_VOLT("ref_gnd", 0, SCALE_HW_CALIB_DEFAULT) - [ADC5_1P25VREF] = ADC5_CHAN_VOLT("vref_1p25", 1, + [ADC5_1P25VREF] = ADC5_CHAN_VOLT("vref_1p25", 0, SCALE_HW_CALIB_DEFAULT) - [ADC5_VPH_PWR] = ADC5_CHAN_VOLT("vph_pwr", 3, + [ADC5_VPH_PWR] = ADC5_CHAN_VOLT("vph_pwr", 1, SCALE_HW_CALIB_DEFAULT) - [ADC5_VBAT_SNS] = ADC5_CHAN_VOLT("vbat_sns", 3, + [ADC5_VBAT_SNS] = ADC5_CHAN_VOLT("vbat_sns", 1, SCALE_HW_CALIB_DEFAULT) - [ADC5_DIE_TEMP] = ADC5_CHAN_TEMP("die_temp", 1, + [ADC5_DIE_TEMP] = ADC5_CHAN_TEMP("die_temp", 0, SCALE_HW_CALIB_PMIC_THERM) - [ADC5_USB_IN_I] = ADC5_CHAN_VOLT("usb_in_i_uv", 1, + [ADC5_USB_IN_I] = ADC5_CHAN_VOLT("usb_in_i_uv", 0, SCALE_HW_CALIB_DEFAULT) - [ADC5_USB_IN_V_16] = ADC5_CHAN_VOLT("usb_in_v_div_16", 16, + [ADC5_USB_IN_V_16] = ADC5_CHAN_VOLT("usb_in_v_div_16", 8, SCALE_HW_CALIB_DEFAULT) - [ADC5_CHG_TEMP] = ADC5_CHAN_TEMP("chg_temp", 1, + [ADC5_CHG_TEMP] = ADC5_CHAN_TEMP("chg_temp", 0, SCALE_HW_CALIB_PM5_CHG_TEMP) /* Charger prescales SBUx and MID_CHG to fit within 1.8V upper unit */ - [ADC5_SBUx] = ADC5_CHAN_VOLT("chg_sbux", 3, + [ADC5_SBUx] = ADC5_CHAN_VOLT("chg_sbux", 1, SCALE_HW_CALIB_DEFAULT) - [ADC5_MID_CHG_DIV6] = ADC5_CHAN_VOLT("chg_mid_chg", 6, + [ADC5_MID_CHG_DIV6] = ADC5_CHAN_VOLT("chg_mid_chg", 3, SCALE_HW_CALIB_DEFAULT) - [ADC5_XO_THERM_100K_PU] = ADC5_CHAN_TEMP("xo_therm", 1, + [ADC5_XO_THERM_100K_PU] = ADC5_CHAN_TEMP("xo_therm", 0, SCALE_HW_CALIB_XOTHERM) - [ADC5_AMUX_THM1_100K_PU] = ADC5_CHAN_TEMP("amux_thm1_100k_pu", 1, + [ADC5_AMUX_THM1_100K_PU] = ADC5_CHAN_TEMP("amux_thm1_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) - [ADC5_AMUX_THM2_100K_PU] = ADC5_CHAN_TEMP("amux_thm2_100k_pu", 1, + [ADC5_AMUX_THM2_100K_PU] = ADC5_CHAN_TEMP("amux_thm2_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) - [ADC5_AMUX_THM3_100K_PU] = ADC5_CHAN_TEMP("amux_thm3_100k_pu", 1, + [ADC5_AMUX_THM3_100K_PU] = ADC5_CHAN_TEMP("amux_thm3_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) - [ADC5_AMUX_THM2] = ADC5_CHAN_TEMP("amux_thm2", 1, + [ADC5_AMUX_THM2] = ADC5_CHAN_TEMP("amux_thm2", 0, SCALE_HW_CALIB_PM5_SMB_TEMP) };

static const struct adc5_channels adc5_chans_rev2[ADC5_MAX_CHANNEL] = { - [ADC5_REF_GND] = ADC5_CHAN_VOLT("ref_gnd", 1, + [ADC5_REF_GND] = ADC5_CHAN_VOLT("ref_gnd", 0, SCALE_HW_CALIB_DEFAULT) - [ADC5_1P25VREF] = ADC5_CHAN_VOLT("vref_1p25", 1, + [ADC5_1P25VREF] = ADC5_CHAN_VOLT("vref_1p25", 0, SCALE_HW_CALIB_DEFAULT) - [ADC5_VPH_PWR] = ADC5_CHAN_VOLT("vph_pwr", 3, + [ADC5_VPH_PWR] = ADC5_CHAN_VOLT("vph_pwr", 1, SCALE_HW_CALIB_DEFAULT) - [ADC5_VBAT_SNS] = ADC5_CHAN_VOLT("vbat_sns", 3, + [ADC5_VBAT_SNS] = ADC5_CHAN_VOLT("vbat_sns", 1, SCALE_HW_CALIB_DEFAULT) - [ADC5_VCOIN] = ADC5_CHAN_VOLT("vcoin", 3, + [ADC5_VCOIN] = ADC5_CHAN_VOLT("vcoin", 1, SCALE_HW_CALIB_DEFAULT) - [ADC5_DIE_TEMP] = ADC5_CHAN_TEMP("die_temp", 1, + [ADC5_DIE_TEMP] = ADC5_CHAN_TEMP("die_temp", 0, SCALE_HW_CALIB_PMIC_THERM) - [ADC5_AMUX_THM1_100K_PU] = ADC5_CHAN_TEMP("amux_thm1_100k_pu", 1, + [ADC5_AMUX_THM1_100K_PU] = ADC5_CHAN_TEMP("amux_thm1_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) - [ADC5_AMUX_THM2_100K_PU] = ADC5_CHAN_TEMP("amux_thm2_100k_pu", 1, + [ADC5_AMUX_THM2_100K_PU] = ADC5_CHAN_TEMP("amux_thm2_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) - [ADC5_AMUX_THM3_100K_PU] = ADC5_CHAN_TEMP("amux_thm3_100k_pu", 1, + [ADC5_AMUX_THM3_100K_PU] = ADC5_CHAN_TEMP("amux_thm3_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) - [ADC5_AMUX_THM4_100K_PU] = ADC5_CHAN_TEMP("amux_thm4_100k_pu", 1, + [ADC5_AMUX_THM4_100K_PU] = ADC5_CHAN_TEMP("amux_thm4_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) - [ADC5_AMUX_THM5_100K_PU] = ADC5_CHAN_TEMP("amux_thm5_100k_pu", 1, + [ADC5_AMUX_THM5_100K_PU] = ADC5_CHAN_TEMP("amux_thm5_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) - [ADC5_XO_THERM_100K_PU] = ADC5_CHAN_TEMP("xo_therm_100k_pu", 1, + [ADC5_XO_THERM_100K_PU] = ADC5_CHAN_TEMP("xo_therm_100k_pu", 0, SCALE_HW_CALIB_THERM_100K_PULLUP) };

@@ -558,6 +559,9 @@ static int adc5_get_dt_channel_data(struct adc5_chip *adc, return ret; } prop->prescale = ret; + } else { + prop->prescale = + adc->data->adc_chans[prop->channel].prescale_index; }

ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);