This is a note to let you know that I've just added the patch titled
iio: adc: xilinx-xadc: Don't clobber preset voltage/temperature thresholds
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iio-adc-xilinx-xadc-don-t-clobber-preset-voltage-temperature-thresholds.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8d6b3ea4d9eaca80982442b68a292ce50ce0a135 Mon Sep 17 00:00:00 2001
From: Robert Hancock <robert.hancock@xxxxxxxxxx>
Date: Thu, 14 Sep 2023 18:10:18 -0600
Subject: iio: adc: xilinx-xadc: Don't clobber preset voltage/temperature thresholds
From: Robert Hancock <robert.hancock@xxxxxxxxxx>
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@xxxxxxxxxx>
Acked-by: O'Griofa, Conall <conall.ogriofa@xxxxxxx>
Tested-by: O'Griofa, Conall <conall.ogriofa@xxxxxxx>
Link: https://lore.kernel.org/r/20230915001019.2862964-2-robert.hancock@xxxxxxxxxx
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -1434,28 +1434,6 @@ 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);
Patches currently in stable-queue which might be from robert.hancock@xxxxxxxxxx are
queue-5.15/iio-adc-xilinx-xadc-don-t-clobber-preset-voltage-temperature-thresholds.patch
queue-5.15/iio-adc-xilinx-xadc-correct-temperature-offset-scale-for-ultrascale.patch
