6.1-stable review patch. If anyone has any objections, please let me know.
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From: Robert Hancock robert.hancock@calian.com
commit 8d6b3ea4d9eaca80982442b68a292ce50ce0a135 upstream.
In the probe function, the driver was reading out the thresholds already set in the core, which can be configured by the user in the Vivado tools when the FPGA image is built. However, it later clobbered those values with zero or maximum values. In particular, the overtemperature shutdown threshold register was overwritten with the max value, which effectively prevents the FPGA from shutting down when the desired threshold was eached, potentially risking hardware damage in that case.
Remove this code to leave the preconfigured default threshold values intact.
The code was also disabling all alarms regardless of what enable state they were left in by the FPGA image, including the overtemperature shutdown feature. Leave these bits in their original state so they are not unconditionally disabled.
Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver") Signed-off-by: Robert Hancock robert.hancock@calian.com Acked-by: O'Griofa, Conall conall.ogriofa@amd.com Tested-by: O'Griofa, Conall conall.ogriofa@amd.com Link: https://lore.kernel.org/r/20230915001019.2862964-2-robert.hancock@calian.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/adc/xilinx-xadc-core.c | 22 ---------------------- 1 file changed, 22 deletions(-)
--- a/drivers/iio/adc/xilinx-xadc-core.c +++ b/drivers/iio/adc/xilinx-xadc-core.c @@ -1426,28 +1426,6 @@ static int xadc_probe(struct platform_de if (ret) return ret;
- /* Disable all alarms */ - ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_ALARM_MASK, - XADC_CONF1_ALARM_MASK); - if (ret) - return ret; - - /* Set thresholds to min/max */ - for (i = 0; i < 16; i++) { - /* - * Set max voltage threshold and both temperature thresholds to - * 0xffff, min voltage threshold to 0. - */ - if (i % 8 < 4 || i == 7) - xadc->threshold[i] = 0xffff; - else - xadc->threshold[i] = 0; - ret = xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(i), - xadc->threshold[i]); - if (ret) - return ret; - } - /* Go to non-buffered mode */ xadc_postdisable(indio_dev);