From d61784e6410f3df2028e6eb91b06ffed37a660e0 Mon Sep 17 00:00:00 2001 From: Patrick Delaunay Date: Fri, 18 Nov 2022 06:39:21 +0000 Subject: [PATCH] nvmem: stm32: add warning when upper OTPs are updated As the upper OTPs are ECC protected, they support only one 32 bits word programming. For a second modification of this word, these ECC become invalid and this OTP will be no more accessible, the shadowed value is invalid. This patch adds a warning to indicate an upper OTP update, because this operation is dangerous as OTP is not locked by the driver after the first update to avoid a second update. Signed-off-by: Patrick Delaunay Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20221118063932.6418-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/stm32-romem.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/nvmem/stm32-romem.c +++ b/drivers/nvmem/stm32-romem.c @@ -132,6 +132,9 @@ static int stm32_bsec_write(void *contex } } + if (offset + bytes >= priv->lower * 4) + dev_warn(dev, "Update of upper OTPs with ECC protection (word programming, only once)\n"); + return 0; }