Hi Uwe,
thanks for the review!
> > +.RI [ data ]
> > +.RI [ desc
> > +.RI [ data ]]
>
> You could join the previous two lines.
Try it. You will miss some spaces, then.
> > +Also, you cannot be interrupted by another I2C master during one transfer, but it might happen between multiple transfers.
>
> Well, unless you loose arbitration. Maybe this is too picky to be
> relevant here?
I wonder: will another I2C master start a transfer on a repeated start?
Need to investigate.
> Also in single-master setups you can be interrupted if a driver chooses
> to start sending a transfer between two of yours. I think this is the
> more relevant reason you want to use a single transfer.
Yes, true. I updated the paragraph.
> > + if (!(funcs & I2C_FUNC_I2C)) {
> > + fprintf(stderr, MISSING_FUNC_FMT, "I2C transfers");
> > + return -1;
> > + }
>
> Do you need this check? I hope the kernel doesn't rely on userspace to
> not send a transfer the adapter doesn't support? If the kernel checks
> appropriatly it's a waste of time to duplicate the check in i2ctransfer?
Other I2C tools do it also, so I did as well for consistency reasons. I'd
think, if we fix it, we do it altogether on all tools. In a seperate
series.
> > + fprintf(stderr, "WARNING! This program can confuse your I2C bus, cause data loss and worse!\n");
>
> Does it kill kittens? :-)
I hope not! :) Again, I copied this line from other I2C tools.
> > + struct i2c_msg msgs[I2C_RDRW_IOCTL_MAX_MSGS];
>
> Should this limit be described in the man page?
Good idea, done now.
> > + switch (*arg_ptr++) {
> > + case 'r': flags |= I2C_M_RD; break;
>
> This doesn't match kernel coding style and I'd put it on separate lines.
It's i2c-tools coding style ;)
> > + exit(0);
>
> return EXIT_SUCCESS; ?
Maybe. I'd vote for a seperate series for that again, though.
> > + for (i = 0; i <= nmsgs; i++)
> > + free(msgs[i].buf);
> > +
> > + exit(1);
>
> return EXIT_FAILURE; ?
>
> Apart from the exit code this is exactly the trailer of the good path,
> so these could share code.
No! One has '< nmsgs', the other one '<= nmsgs'. Friendly rant: It was
all easier and less subtle before Jean wanted the 'don't rely on the OS
for cleanup' additions ;)
Regards,
Wolfram
