Hi Jocke, On Wed, 24 Oct 2007 23:06:13 +0200, Tjernlund wrote: > While browsing the i2c-mpc.c driver I noticed some things that look odd > to me so I figured I report them. Could not find a maintainer in the > MAINTANERS file > so I sent here, cc:ed linuxppc-dev as well. > > 1) There are a lot of return -1 error code that is propagated back to > userspace. Should be changed to proper -Exxx codes.
This is true of many Linux i2c bus drivers, unfortunately. While nothing actually prevents drivers from returning -1 to userspace on error, meaningful error codes would of course be preferred. > 2) mpc_read(), according to the comment below it sends a STOP condition here > but > this function does not known if this is the last read or not. mpc_xfer is > the one that knows when the transaction is over and should send the stop, > which it already > does. > > /* Generate stop on last byte */ > if (i == length - 1) > writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_TXAK); Probably correct, although I am not familiar with this specific hardware. I guess that the same is true of mpc_write as well, which is even worse because write + read combined transactions are very common (while read + write are not.) I'm not completely sure that mpc_xfer sends the stop. mpc_i2c_stop doesn't seem to do much. Now that you've identified these bugs, what about sending patches to fix them? -- Jean Delvare _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
