1 files changed, 34 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.15/808-v6.2-0002-nvmem-stm32-add-warning-when-upper-OTPs-are-updated.patch b/target/linux/generic/backport-5.15/808-v6.2-0002-nvmem-stm32-add-warning-when-upper-OTPs-are-updated.patch
new file mode 100644
index 0000000000..5791df2606
--- /dev/null
+++ b/target/linux/generic/backport-5.15/808-v6.2-0002-nvmem-stm32-add-warning-when-upper-OTPs-are-updated.patch
@@ -0,0 +1,34 @@
+From d61784e6410f3df2028e6eb91b06ffed37a660e0 Mon Sep 17 00:00:00 2001
+From: Patrick Delaunay <patrick.delaunay@foss.st.com>
+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 <patrick.delaunay@foss.st.com>
+Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+Link: https://lore.kernel.org/r/20221118063932.6418-3-srinivas.kandagatla@linaro.org
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ 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;
+ }
+