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? Chip doesn't support 0-length transactions, and your code trying to start 1-byte transaction without writing any data to the output FIFO. IBM IIC is broken enough and I don't see any point in such hacks. 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). > ===== 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;
