On Sun, May 21, 2017 at 03:46:20PM +0200, Andreas Noever wrote: > On Thu, May 18, 2017 at 4:38 PM, Mika Westerberg > <mika.westerb...@linux.intel.com> wrote: > > At least Falcon Ridge when in host mode does not have any kind of DROM > > available and reading DROM offset returns 0 for these. Do not try to > > read DROM any further in that case. > > > > Signed-off-by: Mika Westerberg <mika.westerb...@linux.intel.com> > > Reviewed-by: Yehezkel Bernat <yehezkel.ber...@intel.com> > > Reviewed-by: Michael Jamet <michael.ja...@intel.com> > > --- > > drivers/thunderbolt/eeprom.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > Hi Mika, > > nice work, it is nice to see Intel contribute to the Thunderbolt > driver (I can second Lukas's 'jaw drop' comment)! > > I will try to read through everything today, but maybe the last few > patches will get pushed back to next weekend.
Thanks :) > > diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c > > index 6392990c984d..e4e64b130514 100644 > > --- a/drivers/thunderbolt/eeprom.c > > +++ b/drivers/thunderbolt/eeprom.c > > @@ -276,6 +276,9 @@ int tb_drom_read_uid_only(struct tb_switch *sw, u64 > > *uid) > > if (res) > > return res; > > > > + if (drom_offset == 0) > > + return -ENODEV; > > + > I think that this will make tb_switch_resume bail out on the root > switch, which is not good. Since the uid is only used to detect > whether a different device was plugged in while the system was > suspended I think that we can safely ignore the uid on the root > switch: > - don't read it in tb_drom_read (route == 0 is already special cased anyways) > - add a special case for the root switch to tb_switch_resume and > don't read the uid - just assume that it did not change (should be > impossible anyways) > > What do you think? I think there actually is such check already in tb_switch_resume() where we special case the root switch ignoring its UID. Unless I'm missing something. I'm testing this on a Mac with Cactus Ridge and the root switch resume does not fail :)