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 <[email protected]>
---
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 354be526897f..e3c3c333b5d1 100644
--- a/drivers/nvmem/stm32-romem.c
+++ b/drivers/nvmem/stm32-romem.c
@@ -133,6 +133,9 @@ 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
Inform NVMEM framework of type attribute for stm32-romem as NVMEM_TYPE_OTP
so userspace is able to know how the data is stored in BSEC.
Signed-off-by: Patrick Delaunay <[email protected]>
---
drivers/nvmem/stm32-romem.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c
index e3c3c333b5d1..7b3a5a5a64b0 100644
--- a/drivers/nvmem/stm32-romem.c
+++ b/drivers/nvmem/stm32-romem.c
@@ -161,6 +161,7 @@ static int stm32_romem_probe(struct platform_device *pdev)
priv->cfg.dev = dev;
priv->cfg.priv = priv;
priv->cfg.owner = THIS_MODULE;
+ priv->cfg.type = NVMEM_TYPE_OTP;
cfg = (const struct stm32_romem_cfg *)
of_match_device(dev->driver->of_match_table, dev)->data;
--
2.25.1
Hi,
On 10/14/22 17:04, Patrick Delaunay wrote:
> 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 <[email protected]>
> ---
>
> 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 354be526897f..e3c3c333b5d1 100644
> --- a/drivers/nvmem/stm32-romem.c
> +++ b/drivers/nvmem/stm32-romem.c
> @@ -133,6 +133,9 @@ static int stm32_bsec_write(void *context, unsigned int offset, void *buf,
> }
> }
>
> + if (offset + bytes >= priv->lower * 4)
Here I miss a dependency for "priv->lower" with a other preliminary
patch for STM32MP13x support.
> + dev_warn(dev, "Update of upper OTPs with ECC protection (word programming, only once)\n");
> +
> return 0;
> }
>
Sorry,
I will sent a V2 soon
Patrick
Hi Patrick,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on atorgue-stm32/stm32-next]
[also build test ERROR on linus/master v6.1-rc1 next-20221017]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Patrick-Delaunay/nvmem-stm32-add-warning-when-upper-OTPs-are-updated/20221017-102514
base: https://git.kernel.org/pub/scm/linux/kernel/git/atorgue/stm32.git stm32-next
patch link: https://lore.kernel.org/r/20221014170426.1.Ifa806ff30d7c669ba9a3df9c6b64698a2dcc073a%40changeid
patch subject: [PATCH 1/2] nvmem: stm32: add warning when upper OTPs are updated
config: arc-randconfig-r023-20221017
compiler: arceb-elf-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/2f808f51f933798336822a96450c2c2797c2acc6
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Patrick-Delaunay/nvmem-stm32-add-warning-when-upper-OTPs-are-updated/20221017-102514
git checkout 2f808f51f933798336822a96450c2c2797c2acc6
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash drivers/gpio/ drivers/nvmem/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
drivers/nvmem/stm32-romem.c: In function 'stm32_bsec_write':
>> drivers/nvmem/stm32-romem.c:136:35: error: 'struct stm32_romem_priv' has no member named 'lower'
136 | if (offset + bytes >= priv->lower * 4)
| ^~
vim +136 drivers/nvmem/stm32-romem.c
114
115 static int stm32_bsec_write(void *context, unsigned int offset, void *buf,
116 size_t bytes)
117 {
118 struct stm32_romem_priv *priv = context;
119 struct device *dev = priv->cfg.dev;
120 u32 *buf32 = buf;
121 int ret, i;
122
123 /* Allow only writing complete 32-bits aligned words */
124 if ((bytes % 4) || (offset % 4))
125 return -EINVAL;
126
127 for (i = offset; i < offset + bytes; i += 4) {
128 ret = stm32_bsec_smc(STM32_SMC_PROG_OTP, i >> 2, *buf32++,
129 NULL);
130 if (ret) {
131 dev_err(dev, "Can't write data%d (%d)\n", i >> 2, ret);
132 return ret;
133 }
134 }
135
> 136 if (offset + bytes >= priv->lower * 4)
137 dev_warn(dev, "Update of upper OTPs with ECC protection (word programming, only once)\n");
138
139 return 0;
140 }
141
--
0-DAY CI Kernel Test Service
https://01.org/lkp