Hi, Has the patch been accepted? Regards, Yuantian > -----Original Message----- > From: Jean Delvare [mailto:khali@xxxxxxxxxxxx] > Sent: 2011年11月17日 3:19 > To: sun york-R58495 > Cc: guenter.roeck@xxxxxxxxxxxx; Tabi Timur-B04825; linux- > i2c@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Tang Yuantian-B29983 > Subject: Re: [PATCH] i2c/busses: (mpc) Add support for > SMBUS_READ_BLOCK_DATA > > On Wed, 16 Nov 2011 11:15:15 -0800, York Sun wrote: > > On Wed, 2011-11-16 at 20:10 +0100, Jean Delvare wrote: > > > On Wed, 16 Nov 2011 10:20:38 -0800, York Sun wrote: > > > > On Wed, 2011-11-16 at 19:09 +0100, Jean Delvare wrote: > > > > > Your thinking is too focused on I2C block reads (or even block > > > > > read of data over the network or on disk). SMBus block read is > > > > > something completely different. It's not about reading 200 bytes > > > > > of data and receiving it in 16-byte chunks (I2C block read works > > > > > that way, on EEPROMs in particular.) There is no "data length" > > > > > and "block size" to compare to each other. It's about reading > > > > > the value of _one_ register and this value happens to be > > > > > multi-byte. There is typically _no_ register pointer increment > > > > > (automatic or not) involved as can happen with EEPROMs. If an > > > > > SMBus block read from register N returns 10 bytes, you're not > > > > > going to read the next 10 bytes from register N+10. There are no > > > > > "next 10 bytes" to read, and register N+10 is something > completely unrelated. > > > > > > > > > > And for this reason, it is not possible to mix SMBus block reads > > > > > with byte reads, as can be done with I2C block reads. > > > > > > > > > > Also note that there is a limit of 32 bytes for SMBus block > > > > > transfers, per SMBus specification. All slaves and masters must > comply with it. > > > > > > > > > > I hope I managed to clarify the case this time... > > > > > > > > You have made it much clear. If block size is fixed and block read > > > > cannot mix with byte read, shall we do this > > > > > > > > if length < block_size > > > > read block_size > > > > else { > > > > while (length) { > > > > read block_size > > > > length -= block_size > > > > } > > > > > > Which part of > > > > > > There is no "data length" and "block size" to compare to each other. > > > > > > did you not understand? > > > > For example, if the length is 40 and the block size is 32, are you > > going to read 32, 72 byte or 64 byte? > > The length is not 40. Which part of > > Also note that there is a limit of 32 bytes for SMBus block transfers, > per SMBus specification. All slaves and masters must comply with it. > > did you now understand? > > Really, please. I understand you're only trying to help and understand > the patch, but at some point, if you have zero knowledge about the topic, > you're not the right person to review the patch, period. You are still > welcome to test the patch if you can and want, that's a completely > different task. > > -- > Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
