The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 56e4f2dda23c6d39d327944faa89efaa4eb290d1 Mon Sep 17 00:00:00 2001

From: Gwendal Grignou gwendal@chromium.org Date: Tue, 30 Jun 2020 08:37:30 -0700 Subject: [PATCH] iio: cros_ec: Use default frequencies when EC returns invalid information

Minimal and maximal frequencies supported by a sensor is queried. On some older machines, these frequencies are not returned properly and the EC returns 0 instead. When returned maximal frequency is 0, ignore the information and use default frequencies instead.

Fixes: ae7b02ad2f32 ("iio: common: cros_ec_sensors: Expose cros_ec_sensors frequency range via iio sysfs") Signed-off-by: Gwendal Grignou gwendal@chromium.org Reviewed-by: Enric Balletbo i Serra enric.balletbo@collabora.com Link: https://lore.kernel.org/r/20200630153730.3302889-1-gwendal@chromium.org CC: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c index c62cacc04672..e3f507771f17 100644 --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c @@ -256,7 +256,7 @@ int cros_ec_sensors_core_init(struct platform_device *pdev, struct cros_ec_sensorhub *sensor_hub = dev_get_drvdata(dev->parent); struct cros_ec_dev *ec = sensor_hub->ec; struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev); - u32 ver_mask; + u32 ver_mask, temp; int frequencies[ARRAY_SIZE(state->frequencies) / 2] = { 0 }; int ret, i;

@@ -311,10 +311,16 @@ int cros_ec_sensors_core_init(struct platform_device *pdev, &frequencies[2], &state->fifo_max_event_count); } else { - frequencies[1] = state->resp->info_3.min_frequency; - frequencies[2] = state->resp->info_3.max_frequency; - state->fifo_max_event_count = - state->resp->info_3.fifo_max_event_count; + if (state->resp->info_3.max_frequency == 0) { + get_default_min_max_freq(state->resp->info.type, + &frequencies[1], + &frequencies[2], + &temp); + } else { + frequencies[1] = state->resp->info_3.min_frequency; + frequencies[2] = state->resp->info_3.max_frequency; + } + state->fifo_max_event_count = state->resp->info_3.fifo_max_event_count; } for (i = 0; i < ARRAY_SIZE(frequencies); i++) { state->frequencies[2 * i] = frequencies[i] / 1000;