On Fri, May 18, 2007 at 04:48:13PM +0200, e9hack wrote: > Johannes Stezenbach wrote: > > According to linux/Documentation/i2c/i2c-protocol.txt the correct > > way to get a STOP condition between two I2C messages is send them > > in seperate I2C transactions. > > I don't find this description in i2c-protocol. It's not written explicitly, but it says you need to use a "Simple send transaction" and/or a "Simple receive transaction" instead of a "Combined transaction" if you want a STOP bit in between. That's how i2c-core is designed. > IMHO, it isn't possible > to split a read request into a single write and a single read request > outside of the core device. The device must be locked during both > transfers. If the device isn't locked, it is possible that another > transfer will change the slave offset before the content is read. This > may occur with the current implementation. If locking is necessary the drivers would need to handle this explicitely (I think it isn't unless ou start messing mith /dev/i2c concurrently). Or you could propose a change to i2c-core to add a I2C_M_STOP flag (analogous to I2C_M_NOSTART), which then would have to be implemented by all i2c bus drivers. > > If i2cdump is not able to handle > > this, please fix i2cdump. > > I2cdump deals with /dev/i2c and has nothing to do with this problem. Then why did you say i2cdump is "not able to read the registers from the stv0297"? Johannes _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
