Messages in this thread | | | From | Andreas Noever <> | Date | Sun, 21 May 2017 15:46:20 +0200 | Subject | Re: [PATCH 02/24] thunderbolt: Do not try to read UID if DROM offset is read as 0 |
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On Thu, May 18, 2017 at 4:38 PM, Mika Westerberg <mika.westerberg@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.westerberg@linux.intel.com> > Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com> > Reviewed-by: Michael Jamet <michael.jamet@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.
> 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?
Andreas
> /* read uid */ > res = tb_eeprom_read_n(sw, drom_offset, data, 9); > if (res) > -- > 2.11.0 >
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