drivers/i2c/busses/i2c-i801.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-)
If SPD Write Disable bit in the SMBus is enabled, writing data to
addresses from 0x50 to 0x57 is forbidden. This may lead to the
following issues for spd5118 devices:
1) Writes to the sensor hwmon sysfs attributes will always result
in ENXIO.
2) During system-wide resume, errors may occur during regcache sync,
resulting in the following error messages:
kernel: spd5118 1-0050: failed to write b = 0: -6
kernel: spd5118 1-0050: pm: dpm_run_callback(): spd5118_resume [spd5118] returns -6
kernel: spd5118 1-0050: pm: failed to resume async: error -6
3) nvmem won't be usable, because writing to the page selector becomes
impossible.
Also, BIOS vendors may choose to set the page to a value != 0 after a board
reset. This will make the sensor not functional unless its MR11 register
can be changed, which is impossible due to writes being disabled.
To address these issues, don't instantiate it at all if the SPD Write Disable
bit is set.
Signed-off-by: Yo-Jung Lin (Leo) <leo.lin@canonical.com>
---
This is intended to be the fixed version of the second patch in the
following patch series[1]:
[PATCH v2 0/2] i2c: i801: don't instantiate spd5118 under SPD Write Disable
The original version got reverted due to breaking i386 defconfig build.
However the first patch in that series didn't. To avoid the first patch in
the series being repeatedly sent and applied, this is sent as a separate
patch.
Also not pulling Reviewed-by from Guenter because the patch differs from
what was originally reviewed.
[1] https://lore.kernel.org/all/20250430-for-upstream-i801-spd5118-no-instantiate-v2-0-2f54d91ae2c7@canonical.com/
---
drivers/i2c/busses/i2c-i801.c | 28 +++++++++++++++++++++++-----
1 file changed, 23 insertions(+), 5 deletions(-)
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index a7f89946dad4..de17532402b9 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -1157,6 +1157,27 @@ static void dmi_check_onboard_devices(const struct dmi_header *dm, void *adap)
}
}
+static void __i801_register_spd(struct i801_priv *priv)
+{
+ if (priv->original_hstcfg & SMBHSTCFG_SPD_WD)
+ i2c_register_spd_write_disable(&priv->adapter);
+ else
+ i2c_register_spd_write_enable(&priv->adapter);
+}
+
+#ifdef CONFIG_I2C_I801_MUX
+static void i801_register_spd(struct i801_priv *priv)
+{
+ if (!priv->mux_pdev)
+ __i801_register_spd(priv);
+}
+#else
+static void i801_register_spd(struct i801_priv *priv)
+{
+ __i801_register_spd(priv);
+}
+#endif
+
/* Register optional targets */
static void i801_probe_optional_targets(struct i801_priv *priv)
{
@@ -1177,10 +1198,7 @@ static void i801_probe_optional_targets(struct i801_priv *priv)
dmi_walk(dmi_check_onboard_devices, &priv->adapter);
/* Instantiate SPD EEPROMs unless the SMBus is multiplexed */
-#ifdef CONFIG_I2C_I801_MUX
- if (!priv->mux_pdev)
-#endif
- i2c_register_spd_write_enable(&priv->adapter);
+ i801_register_spd(priv);
}
#else
static void __init input_apanel_init(void) {}
@@ -1283,7 +1301,7 @@ static int i801_notifier_call(struct notifier_block *nb, unsigned long action,
return NOTIFY_DONE;
/* Call i2c_register_spd for muxed child segments */
- i2c_register_spd_write_enable(to_i2c_adapter(dev));
+ __i801_register_spd(priv);
return NOTIFY_OK;
}
---
base-commit: 176e917e010cb7dcc605f11d2bc33f304292482b
change-id: 20250526-for-upstream-not-instantiate-spd5118-463225b346a0
Best regards,
--
Yo-Jung (Leo) Lin <leo.lin@canonical.com>Hi Yo-Jung,
kernel test robot noticed the following build errors:
[auto build test ERROR on 176e917e010cb7dcc605f11d2bc33f304292482b]
url: https://github.com/intel-lab-lkp/linux/commits/Yo-Jung-Leo-Lin/i2c-i801-Do-not-instantiate-spd5118-under-SPD-Write-Disable/20250528-163253
base: 176e917e010cb7dcc605f11d2bc33f304292482b
patch link: https://lore.kernel.org/r/20250528-for-upstream-not-instantiate-spd5118-v1-1-8216e2d38918%40canonical.com
patch subject: [PATCH] i2c: i801: Do not instantiate spd5118 under SPD Write Disable
config: loongarch-randconfig-001-20250529 (https://download.01.org/0day-ci/archive/20250529/202505290728.VsNgBfDO-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250529/202505290728.VsNgBfDO-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202505290728.VsNgBfDO-lkp@intel.com/
All errors (new ones prefixed by >>):
drivers/i2c/busses/i2c-i801.c: In function 'i801_notifier_call':
>> drivers/i2c/busses/i2c-i801.c:1304:9: error: implicit declaration of function '__i801_register_spd' [-Wimplicit-function-declaration]
1304 | __i801_register_spd(priv);
| ^~~~~~~~~~~~~~~~~~~
vim +/__i801_register_spd +1304 drivers/i2c/busses/i2c-i801.c
1291
1292 static int i801_notifier_call(struct notifier_block *nb, unsigned long action,
1293 void *data)
1294 {
1295 struct i801_priv *priv = container_of(nb, struct i801_priv, mux_notifier_block);
1296 struct device *dev = data;
1297
1298 if (action != BUS_NOTIFY_ADD_DEVICE ||
1299 dev->type != &i2c_adapter_type ||
1300 i2c_root_adapter(dev) != &priv->adapter)
1301 return NOTIFY_DONE;
1302
1303 /* Call i2c_register_spd for muxed child segments */
> 1304 __i801_register_spd(priv);
1305
1306 return NOTIFY_OK;
1307 }
1308
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On Thu, May 29, 2025 at 8:00 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Yo-Jung,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on 176e917e010cb7dcc605f11d2bc33f304292482b]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Yo-Jung-Leo-Lin/i2c-i801-Do-not-instantiate-spd5118-under-SPD-Write-Disable/20250528-163253
> base: 176e917e010cb7dcc605f11d2bc33f304292482b
> patch link: https://lore.kernel.org/r/20250528-for-upstream-not-instantiate-spd5118-v1-1-8216e2d38918%40canonical.com
> patch subject: [PATCH] i2c: i801: Do not instantiate spd5118 under SPD Write Disable
> config: loongarch-randconfig-001-20250529 (https://download.01.org/0day-ci/archive/20250529/202505290728.VsNgBfDO-lkp@intel.com/config)
> compiler: loongarch64-linux-gcc (GCC) 15.1.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250529/202505290728.VsNgBfDO-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202505290728.VsNgBfDO-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> drivers/i2c/busses/i2c-i801.c: In function 'i801_notifier_call':
> >> drivers/i2c/busses/i2c-i801.c:1304:9: error: implicit declaration of function '__i801_register_spd' [-Wimplicit-function-declaration]
> 1304 | __i801_register_spd(priv);
> | ^~~~~~~~~~~~~~~~~~~
>
>
> vim +/__i801_register_spd +1304 drivers/i2c/busses/i2c-i801.c
>
> 1291
> 1292 static int i801_notifier_call(struct notifier_block *nb, unsigned long action,
> 1293 void *data)
> 1294 {
> 1295 struct i801_priv *priv = container_of(nb, struct i801_priv, mux_notifier_block);
> 1296 struct device *dev = data;
> 1297
> 1298 if (action != BUS_NOTIFY_ADD_DEVICE ||
> 1299 dev->type != &i2c_adapter_type ||
> 1300 i2c_root_adapter(dev) != &priv->adapter)
> 1301 return NOTIFY_DONE;
> 1302
> 1303 /* Call i2c_register_spd for muxed child segments */
> > 1304 __i801_register_spd(priv);
> 1305
> 1306 return NOTIFY_OK;
> 1307 }
> 1308
I think this happens likely because I put the __i801_register_spd() inside the:
#if defined CONFIG_X86 && defined CONFIG_DMI
...
#endif
So the function went missing in loongarch. Will fix this in v2.
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
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