On 10/15/21 7:33 PM, Wilson, David T. (GSFC-5870) wrote:
On my target platform, I do not believe the i2c-tools are completely supported, so i2c-dump is unable to provide me a register dump for the connected tmp461.
No problem. That means though that I won't be able to run a module test,
and I'll have to wait for you or someone else to test my patch
before I can apply it.
Thanks,
Guenter
If you have any other suggested methods of achieving the i2c register dump, I could try those as well.
I see on a different email chain that you have already submitted a patch to resolve this tmp461 issue.
Thanks for looking into this issue!
David
From: Guenter Roeck <groeck7@xxxxxxxxx> on behalf of Guenter Roeck <linux@xxxxxxxxxxxx>
Sent: Friday, October 15, 2021 6:27 PM
To: Wilson, David T. (GSFC-5870) <david.wilson@xxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx>; linux-hwmon@xxxxxxxxxxxxxxx <linux-hwmon@xxxxxxxxxxxxxxx>
Subject: [EXTERNAL] Re: Potential issue with smb word operations for tmp461 device in tmp401 driver
Hi,
On Fri, Oct 15, 2021 at 05:43:54PM +0000, Wilson, David T. (GSFC-5870) wrote:
Hi,
I am reporting what I believe is a potential issue in the tmp401 driver for the tmp461 device specifically. I am new to reporting issues, so I apologize in advance if I've provided insufficient information for an issue report.
The problem I'm encountering is that when I use the tmp401 linux driver to read temperature values from the tmp461, all of the read temperature values end with 996 (e.g. 33996, 38996, etc...).
Looking further into the tmp401 commit messages, I see that the driver was changed to use smb word operations instead of separate byte operations. Although the other supported devices (i.e. tmp432, etc...) are noted to support 16-bit read operations in their respective datasheets, I see no indications of 16-bit read support in the tmp461 datasheet, which is supported by my inquiry in the TI forums (https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fe2e.ti.com%2Fsupport%2Fsensors-group%2Fsensors%2Ff%2Fsensors-forum%2F1044935%2Ftmp461-linux-driver-support-and-16-bit-temperature-register-reads&data=04%7C01%7Cdavid.wilson%40nasa.gov%7C1d874c8a8c8e471a2c1a08d9902af71b%7C7005d45845be48ae8140d43da96dd17b%7C0%7C0%7C637699336485905564%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=vwnJOlMAKMn752Vw%2F11KA96%2BPwnen22GvuT6fcitMt8%3D&reserved=0).
Reverting the driver to the commit before the smb word change, I am then able to read temperature values that do not end only with 996. As a result, I believe that the tmp461 support may be partially broken by the switch to smb word operations.
Thanks a lot for the report. Can you send me a register dump for the tmp461 ?
Thanks,
Guenter
