Hi Greg,

I have not tried to report issues with stable branches before, so my email did reach you[1]. A backported rtc fix was applied incorrectly to linux-6.12.y and linux-6.6.y. Patch message got both incorrect backport commits.

/Bruno

[1] https://lore.kernel.org/stable/20250820193016.7987-1-bruno.thomsen@gmail.com...

Den man. 15. sep. 2025 kl. 00.35 skrev Alexandre Belloni alexandre.belloni@bootlin.com:

Hello Bruno,

I guess you'd have to send this directly to stable and gkh so he wll notice it.

On 20/08/2025 21:30:16+0200, Bruno Thomsen wrote:

...

When commit fa78e9b606a472495ef5b6b3d8b45c37f7727f9d upstream was backported to LTS branches linux-6.12.y and linux-6.6.y, the SPI regmap config fix got applied to the I2C regmap config. Most likely due to a new RTC get/set parm feature introduced in 6.14 causing regmap config sections in the buttom of the driver to move. LTS branch linux-6.1.y and earlier does not have PCF2131 device support.

Issue can be seen in buttom of this diff in stable/linux.git tree: git diff master..linux-6.12.y -- drivers/rtc/rtc-pcf2127.c

Fixes: ee61aec8529e ("rtc: pcf2127: fix SPI command byte for PCF2131") Fixes: 5cdd1f73401d ("rtc: pcf2127: fix SPI command byte for PCF2131") Cc: stable@vger.kernel.org Cc: Alexandre Belloni alexandre.belloni@bootlin.com Cc: Elena Popa elena.popa@nxp.com Cc: Hugo Villeneuve hvilleneuve@dimonoff.com Signed-off-by: Bruno Thomsen bruno.thomsen@gmail.com

---

drivers/rtc/rtc-pcf2127.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c index fc079b9dcf71..502571f0c203 100644 --- a/drivers/rtc/rtc-pcf2127.c +++ b/drivers/rtc/rtc-pcf2127.c @@ -1383,11 +1383,6 @@ static int pcf2127_i2c_probe(struct i2c_client *client) variant = &pcf21xx_cfg[type]; }

• if (variant->type == PCF2131) {
  

•         config.read_flag_mask = 0x0;
  

•         config.write_flag_mask = 0x0;
  

• }
  

• config.max_register = variant->max_register,
  
  regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
  

@@ -1461,6 +1456,11 @@ static int pcf2127_spi_probe(struct spi_device *spi) variant = &pcf21xx_cfg[type]; }

• if (variant->type == PCF2131) {
  

•         config.read_flag_mask = 0x0;
  

•         config.write_flag_mask = 0x0;
  

• }
  

• config.max_register = variant->max_register;
  
  regmap = devm_regmap_init_spi(spi, &config);
  
  

base-commit: 880e4ff5d6c8dc6b660f163a0e9b68b898cc6310

2.50.1

-- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com