[ Upstream commit 20471071f198c8626dbe3951ac9834055b387844 ]
The current implementation of pmbus_show_boolean assumes that all devices
support write-back operation of status register to clear pending warnings
or faults. Since clearing individual bits in the status registers was only
introduced in PMBus specification 1.2, this operation may not be supported
by some older devices. This can result in an error while reading boolean
attributes such as temp1_max_alarm.
Fetch PMBus revision supported by the device and modify pmbus_show_boolean
so that it only tries to clear individual status bits if the device is
compliant with PMBus specs >= 1.2. Otherwise clear all fault indicators
on the current page after a fault status was reported.
Fixes: 35f165f08950a ("hwmon: (pmbus) Clear pmbus fault/warning bits after read")
Signed-off-by: Patryk Biel <pbiel7@gmail.com>
Message-ID: <20240909-pmbus-status-reg-clearing-v1-1-f1c0d68c6408@gmail.com>
[groeck:
Rewrote description
Moved revision detection code ahead of clear faults command
Assigned revision if return value from PMBUS_REVISION command is 0
Improved return value check from calling _pmbus_write_byte_data()]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5de3e13f7f6b496bd7bd9ff4d2b915b7d3e67cda ]
Some of the pmbus core functions uses pmbus_write_byte_data, which does
not support driver callbacks for chip specific write operations. This
could potentially influence some specific regulator chips that for
example need a time delay before each data access.
Lets add support for driver callback with _pmbus_write_byte_data.
Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
Link: https://lore.kernel.org/r/20220428144039.2464667-2-marten.lindahl@axis.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Stable-dep-of: 20471071f198 ("hwmon: (pmbus) Conditionally clear individual status bits for pmbus rev >= 1.2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 26e8383b116d0dbe74e28f86646563ab46d66d83 upstream.
Following the failure observed with a delay of 250us, experiments were
conducted with various delays. It was found that a delay of 350us
effectively mitigated the issue.
To provide a more optimal solution while still allowing a margin for
stability, the delay is being adjusted to 500us.
Signed-off-by: Lakshmi Yadlapati <lakshmiy@us.ibm.com>
Link: https://lore.kernel.org/r/20240507194603.1305750-1-lakshmiy@us.ibm.com
Fixes: 8d655e6523764 ("hwmon: (ucd90320) Add minimum delay between bus accesses")
Reviewed-by: Eddie James <eajames@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
