On Wed, 2 Jun 2021 18:25:21 +0200, Wolfram Sang wrote: > Well, I thought mainly about this patch "tools: i2cbusses: Handle bus > names like /dev/i2c-0" but you took care of it faster than I did. > > There is only one patch left in patchwork from 2016: > > http://patchwork.ozlabs.org/project/linux-i2c/patch/044b3af6a47dfa92e047f0ff57e39a5b61e00058.1463165295.git.leonard.crestez@xxxxxxxxx/ > "[i2c-tools] i2cget: Add support for i2c block data" > > That's all what's left in patchwork. > > Dunno if you care about the old patch, but I think we are good to go for > a release. Yes I do care. Apparently I wasn't Cc'd on that thread so I wasn't even aware that patch existed. It would be very nice if you could bump the thread to me (unless there's a way to retrieve it from patchwork that I didn't find?) I read the thread, my initial answer would have matched Guenter's (as always...) but the contributor has a point, the range option is not supported by i2cdump in I2C block mode. Whether it's better to add support for it there, or in i2cget, I'll see. I think i2cget has my preference, because i2cdump pretty much assumes that I2C block reads retrieve successive 8-bit register values, so you can have block boundaries anywhere without changing the result. As a matter of fact, while i2cdump attempts to make 32-byte I2C block reads, it will transparently handle short reads by issuing additional block reads at arbitrary offsets. This works nicely for EEPROMs but could fail for other devices. If we only want *one* I2C block read at a specified offset then i2cget seems more appropriate indeed. Looking at the code, I see that i2cdump already supports SMBus block mode, in a way which is very similar to what the contributor asked for, i.e. it doesn't really dump the chip's registers, but merely reads one SMBus block at a specific offset. It's questionable why this should belong to i2cdump in the first place, beyond the fact that it returns several values when i2cget typically returns only one value. So one option would be get rid of "s" mode in i2cdump, and add support for both I2C and SMBus block read to i2cget. Might be possible to add support for range limitation to I2C block reads in i2cdump nevertheless, as it could be useful to read only portions of EEPROMs. -- Jean Delvare SUSE L3 Support
