From e9aa2473cf9400a6023b02b8f217c2760021e5ed Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Guillermo=20Rodr=C3=ADguez?= Date: Tue, 26 May 2026 11:12:09 +0200 Subject: [PATCH] i2c: stm32f7: fix timing computation ignoring i2c-analog-filter MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit a124579c0763da7bc408f4cd7e8f606cadc94855 upstream. stm32f7_i2c_compute_timing() uses i2c_dev->analog_filter to pick the analog filter delay, but i2c_dev->analog_filter is parsed from the "i2c-analog-filter" DT property only after the compute_timing loop in stm32f7_i2c_setup_timing(), so in practice the timing calculations always ignore the analog filter. On an STM32MP1 board with clock-frequency = <400000> and i2c-analog-filter set, measured SCL frequency was ~382 kHz. This also affects (widens) the computed SDADEL range. At high bus clock speeds, this can select an SDADEL value that violates tVD;DAT (data valid time). Fix by parsing "i2c-analog-filter" before the compute_timing loop. Fixes: 83c3408f7b9c ("i2c: stm32f7: support DT binding i2c-analog-filter") Signed-off-by: Guillermo Rodríguez Cc: # v5.13+ Acked-by: Alain Volmat Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260526091210.20383-1-guille.rodriguez@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-stm32f7.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index 654776a5c37b..caeddb750006 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -673,6 +673,9 @@ static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev, if (!of_property_read_bool(i2c_dev->dev->of_node, "i2c-digital-filter")) i2c_dev->dnf_dt = STM32F7_I2C_DNF_DEFAULT; + i2c_dev->analog_filter = of_property_read_bool(i2c_dev->dev->of_node, + "i2c-analog-filter"); + do { ret = stm32f7_i2c_compute_timing(i2c_dev, setup, &i2c_dev->timing); @@ -694,9 +697,6 @@ static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev, return ret; } - i2c_dev->analog_filter = of_property_read_bool(i2c_dev->dev->of_node, - "i2c-analog-filter"); - dev_dbg(i2c_dev->dev, "I2C Speed(%i), Clk Source(%i)\n", setup->speed_freq, setup->clock_src); dev_dbg(i2c_dev->dev, "I2C Rise(%i) and Fall(%i) Time\n",