Fixes for 5.4

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-5.4/gpio-74x164-enable-output-pins-after-registers-are-r.patch b/queue-5.4/gpio-74x164-enable-output-pins-after-registers-are-r.patch
new file mode 100644 (file)
index 0000000..82e4cd3
--- /dev/null
+++ b/queue-5.4/gpio-74x164-enable-output-pins-after-registers-are-r.patch
@@ -0,0 +1,57 @@
+From f176ae952d137c9b2efc82c84a6b75fa2ce3df53 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Fri, 1 Mar 2024 09:12:04 +0200
+Subject: gpio: 74x164: Enable output pins after registers are reset
+
+From: Arturas Moskvinas <arturas.moskvinas@gmail.com>
+
+[ Upstream commit 530b1dbd97846b110ea8a94c7cc903eca21786e5 ]
+
+Chip outputs are enabled[1] before actual reset is performed[2] which might
+cause pin output value to flip flop if previous pin value was set to 1.
+Fix that behavior by making sure chip is fully reset before all outputs are
+enabled.
+
+Flip-flop can be noticed when module is removed and inserted again and one of
+the pins was changed to 1 before removal. 100 microsecond flipping is
+noticeable on oscilloscope (100khz SPI bus).
+
+For a properly reset chip - output is enabled around 100 microseconds (on 100khz
+SPI bus) later during probing process hence should be irrelevant behavioral
+change.
+
+Fixes: 7ebc194d0fd4 (gpio: 74x164: Introduce 'enable-gpios' property)
+Link: https://elixir.bootlin.com/linux/v6.7.4/source/drivers/gpio/gpio-74x164.c#L130 [1]
+Link: https://elixir.bootlin.com/linux/v6.7.4/source/drivers/gpio/gpio-74x164.c#L150 [2]
+Signed-off-by: Arturas Moskvinas <arturas.moskvinas@gmail.com>
+Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/gpio/gpio-74x164.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/gpio/gpio-74x164.c b/drivers/gpio/gpio-74x164.c
+index e81307f9754e3..30aa7f82fc5b4 100644
+--- a/drivers/gpio/gpio-74x164.c
++++ b/drivers/gpio/gpio-74x164.c
+@@ -128,8 +128,6 @@ static int gen_74x164_probe(struct spi_device *spi)
+       if (IS_ERR(chip->gpiod_oe))
+               return PTR_ERR(chip->gpiod_oe);
+ 
+-      gpiod_set_value_cansleep(chip->gpiod_oe, 1);
+-
+       spi_set_drvdata(spi, chip);
+ 
+       chip->gpio_chip.label = spi->modalias;
+@@ -154,6 +152,8 @@ static int gen_74x164_probe(struct spi_device *spi)
+               goto exit_destroy;
+       }
+ 
++      gpiod_set_value_cansleep(chip->gpiod_oe, 1);
++
+       ret = gpiochip_add_data(&chip->gpio_chip, chip);
+       if (!ret)
+               return 0;
+-- 
+2.43.0
+

diff --git a/queue-5.4/series b/queue-5.4/series
index a50b2ccfaf7777a52a204cc2489cae3b14618698..eef1e58edcd699fd30f969fee4161675d95829a7 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -23,3 +23,4 @@ fs-aio-make-io_cancel-generate-completions-again.patch
 x86-cpu-intel-detect-tme-keyid-bits-before-setting-mtrr-mask-registers.patch
 cachefiles-fix-memory-leak-in-cachefiles_add_cache.patch
 fs-hugetlb-fix-null-pointer-dereference-in-hugetlbs_fill_super.patch
+gpio-74x164-enable-output-pins-after-registers-are-r.patch