Fri, Dec 27, 2024 at 11:51:54AM +0000, Prabhakar kirjoitti: > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > Introduce a new `riic_bus_barrier()` function to verify bus availability > before initiating an I2C transfer. This function enhances the bus > arbitration check by ensuring that the SDA and SCL lines are not held low, > in addition to checking the BBSY flag using `readb_poll_timeout()`. > > Previously, only the BBSY flag was checked to determine bus availability. > However, it is possible for the SDA line to remain low even when BBSY = 0. > This new implementation performs an additional check on the SDA and SCL > lines to avoid potential bus contention issues. ... > + /* > + * The SDA line can still be low even when BBSY = 0. Therefore, after checking > + * the BBSY flag, also verify that the SDA and SCL lines are not being held low. > + */ > + ret = readb_poll_timeout(riic->base + riic->info->regs[RIIC_ICCR2], val, > + !(val & ICCR2_BBSY), 10, riic->adapter.timeout); > + if (ret) > + return -EBUSY; Why the return code is shadowed? Is it requirement by ABI? > + if ((riic_readb(riic, RIIC_ICCR1) & (ICCR1_SDAI | ICCR1_SCLI)) != > + (ICCR1_SDAI | ICCR1_SCLI)) > + return -EBUSY; > + > + return 0; > +} -- With Best Regards, Andy Shevchenko
