On Mon, 12 Apr 2004 10:43:06 -0700 Eugene Surovegin <ebs at ebshome.net> wrote: > On Mon, Apr 12, 2004 at 03:59:32PM +0400, Evgeniy Polyakov wrote: > > Attached diff against 2.4 kernel fixes "new" (for i2c-ibm_iic) i2c > > initalization path. > > This i2c adapter can't understand commands with zero length so it > > doesn't recognize SMBUS_QUICK command and none chip can be attached > > to this. Patch fixes this cruft. > > Tested on ppc32 with max663x chip attached. > > > > Please review and commit. > > Well, this doesn't look correct. > Could you explain what are you trying to do? Also, why did you change > debugging macros? Because they don't even compile with debug level > 0. > Chip doesn't support 0-length transactions, and your code trying to > start 1-byte transaction without writing any data to the output FIFO. It does support although not fair. I have tested with this (as you say) "hack" max663x chip. > IBM IIC is broken enough and I don't see any point in such hacks. Agree. But it is not point not to fixing at least initialization at least in such manner. > There is another patch I made for MV guys a month ago > (http://kernel.ebshome.net/iic_0_len-2.4.diff, > http://kernel.ebshome.net/iic_0_len-2.6.diff). > > It restores _incorrect_ old driver behavior and most probably I'll > send that version upstream (I'm still waiting for OK from them). Driver with your patch works exactly as driver without it. It always returns 0 with or without any ACK read from bus. It is wrong. I "found" 7 max6634 sensors on the bus. > > > ===== drivers/i2c/i2c-ibm_iic.c 1.4 vs 1.5 ===== > > --- 1.4/drivers/i2c/i2c-ibm_iic.c Fri Jun 27 15:19:03 2003 > > +++ 1.5/drivers/i2c/i2c-ibm_iic.c Fri Apr 9 20:48:20 2004 > > @@ -61,14 +61,14 @@ > > #define DBG_LEVEL 0 > > > > #if DBG_LEVEL > 0 > > -# define DBG(x...) printk(KERN_DEBUG "ibm-iic" ##x) > > +# define DBG(f, x...) printk("ibm-iic" f, ##x) > > #else > > -# define DBG(x...) ((void)0) > > +# define DBG(f, x...) ((void)0) > > #endif > > #if DBG_LEVEL > 1 > > -# define DBG2(x...) DBG( ##x ) > > +# define DBG2(f, x...) DBG( f, x ) > > #else > > -# define DBG2(x...) ((void)0) > > +# define DBG2(f, x...) ((void)0) > > #endif > > #if DBG_LEVEL > 2 > > static void dump_iic_regs(const char* header, struct > > ibm_iic_private* dev) > > @@ -328,6 +328,24 @@ > > return ret; > > } > > > > +static int iic_write_empty(struct ibm_iic_private* dev) > > +{ > > + volatile struct iic_regs *iic = dev->vaddr; > > + int ret = 0; > > + > > + u8 cntl = (in_8(&iic->cntl) & CNTL_AMD) | CNTL_PT; > > + > > + DBG2("%d: xfer_bytes, %d, CNTL = 0x%02x\n", dev->idx, 0, cntl); > > + > > + /* Start transfer */ > > + out_8(&iic->cntl, cntl); > > + > > + /* Wait for completion */ > > + ret = iic_wait_for_tc(dev); > > + > > + return ret > 0 ? 0 : ret; > > +} > > + > > /* > > * Low level master transfer routine > > */ > > @@ -338,6 +356,11 @@ > > char* buf = pm->buf; > > int i, j, loops, ret = 0; > > int len = pm->len; > > + > > + if (len == 0) > > + { > > + return iic_write_empty(dev); > > + } > > > > u8 cntl = (in_8(&iic->cntl) & CNTL_AMD) | CNTL_PT; > > if (pm->flags & I2C_M_RD) > > @@ -445,11 +468,6 @@ > > return -EINVAL; > > } > > for (i = 0; i < num; ++i){ > > - if (unlikely(msgs[i].len <= 0)){ > > - DBG("%d: invalid len %d in msg[%d]\n", dev->idx, > > - msgs[i].len, i); > > - return -EINVAL; > > - } > > if (unlikely(iic_address_neq(&msgs[0], &msgs[i]))){ > > DBG("%d: invalid addr in msg[%d]\n", dev->idx, i); > > return -EINVAL; > > Evgeniy Polyakov ( s0mbre ) Only failure makes us experts. -- Theo de Raadt
