pon., 31 sty 2022 o 14:32 Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> napisał(a): > > On Mon, Jan 31, 2022 at 12:56:27PM +0100, Jan Dąbroś wrote: > > pt., 28 sty 2022 o 16:50 Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > napisał(a): > > > On Fri, Jan 28, 2022 at 03:59:40PM +0100, Jan Dąbroś wrote: > > > > pt., 28 sty 2022 o 15:48 Jan Dabros <jsd@xxxxxxxxxxxx> napisał(a): > > ... > > > > > > +struct psp_mbox { > > > > > + u32 cmd_fields; > > > > > > > > + phys_addr_t i2c_req_addr; > > > > > > But phys_addr_t is platform-dependent type. Perhaps you meant to use u64 > > > here > > > always? > > > > Once I remove the "depends on X86_64" I believe this should be left > > platform-dependent. > > If it's a protocol or HW layout, it may not be platform-dependent. Right you are correct, will keep this as 64bit variable. > > > > > > +} __packed; > > ... > > > > > > + if (psp_send_cmd(req)) > > > > > > > > + return -EIO; > > > > > > Why is error code shadowed? > > > > > > > Just as a side note - it wasn't modified in v2 when moving above to > > psp_send_check_i2c_req(), but let me explain why I have introduced this > > initially. > > > > We have two means of timeouts in the context of this driver: > > 1. Timeout of internal mailbox, which means we cannot communicate with a > > PSP for a programmed timeout. This timeout is encountered inside > > psp_send_cmd(). > > 2. Timeout of i2c arbitration - which means that we can communicate with > > PSP, but PSP refuses to release i2c bus for too long. This timeout is > > returned by psp_send_i2c_req() in case of error. > > (side note: both error conditions are very unlikely to happen at runtime) > > > > I wanted to clearly distinguish between these two and thus put all errors > > around mailbox into "-EIO category", which is actually true. > > At very least this code needs more or less the above to be put as a comment. ACK > > ... > > > > > > +cleanup: > > > > > + mutex_unlock(&psp_i2c_access_mutex); > > > > > + return 0; > > > > > > Not sure I understand why we ignore all above errors here. > > > > > > > Actually we are not ignoring them, since each error sets "psp_i2c_mbox_fail > > = true;". This means that if there is any error on x86-PSP interface, we > > are ignoring i2c-arbitration and just fall back to normal (that is > > no-quirk) operation. > > > > From the i2c-client perspective (who is eventually gathering error code > > from above) I think we can claim that everything is fine, since bus is > > granted to it. For developers there is an error message in case some debug > > will be necessary. > > Perhaps needs a comment (sorry, if I overlooked it). ACK. > > ... > > > > > > + if (!dev || !dev->dev) > > > > > + return -ENODEV; > > > > > > At which circumstances may we get > > > dev != NULL > > > dev->dev == NULL > > > ? > > > > > > ... > > > > > > > > if (!dev || !dev->dev) > > > > > - return 0; > > > > > + return -ENODEV; > > > > > > I see the same here, perhaps Hans knows the answer :-) > > > > Right, so I must admit that I simply used *-baytrail.c as a reference and > > thinking that additional check shouldn't hurt us (always better than not > > enough safety..). Looking more at this now - `dw_i2c_plat_probe()` will > > boil-out earlier if `dev->dev == NULL`. Should I remove this extra check in > > *-baytrail.c in the same commit? > > Maybe. Please, double check that it's not needed indeed. Confirmed that this is unnecessary. Best Regards, Jan > > -- > With Best Regards, > Andy Shevchenko > >