From: Patrick Delaunay <patrick.delaunay@foss.st.com>
To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>
Subject: [PATCH v2 2/3] nvmem: stm32: add warning when upper OTPs are updated
Date: Mon, 17 Oct 2022 17:49:56 +0200 [thread overview]
Message-ID: <20221017174953.v2.2.Ifa806ff30d7c669ba9a3df9c6b64698a2dcc073a@changeid> (raw)
In-Reply-To: <20221017154957.277120-1-patrick.delaunay@foss.st.com>
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>
---
(no changes since v1)
drivers/nvmem/stm32-romem.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c
index d93baee01d7b..bb8aa72ba2f9 100644
--- a/drivers/nvmem/stm32-romem.c
+++ b/drivers/nvmem/stm32-romem.c
@@ -132,6 +132,9 @@ static int stm32_bsec_write(void *context, unsigned int offset, void *buf,
}
}
+ if (offset + bytes >= priv->lower * 4)
+ dev_warn(dev, "Update of upper OTPs with ECC protection (word programming, only once)\n");
+
return 0;
}
--
2.25.1
next prev parent reply other threads:[~2022-10-17 15:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-17 15:49 [PATCH v2 0/3] nvmem: stm32: several minor improvements Patrick Delaunay
2022-10-17 15:49 ` [PATCH v2 1/3] nvmem: stm32: move STM32MP15_BSEC_NUM_LOWER in config Patrick Delaunay
2022-10-17 15:49 ` Patrick Delaunay [this message]
2022-10-17 15:49 ` [PATCH v2 3/3] nvmem: stm32: add nvmem type attribute Patrick Delaunay
2022-10-31 17:41 ` [PATCH v2 0/3] nvmem: stm32: several minor improvements Srinivas Kandagatla
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