From: Jeremy McNicoll <jmcnicol@redhat.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: linux-kernel@vger.kernel.org,
Andreas Noever <andreas.noever@gmail.com>,
Michael Jamet <michael.jamet@intel.com>,
Yehezkel Bernat <yehezkel.bernat@intel.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Mario.Limonciello@dell.com,
Radion Mirchevsky <radion.mirchevsky@intel.com>
Subject: Re: [07/18] thunderbolt: Handle rejected Thunderbolt devices
Date: Tue, 27 Feb 2018 14:27:26 -0800 [thread overview]
Message-ID: <9a0ba004-1420-daa8-3ad1-299faf5ed5a8@redhat.com> (raw)
In-Reply-To: <20180227092627.GD2424@lahna.fi.intel.com>
On 2018-02-27 1:26 AM, Mika Westerberg wrote:
> On Mon, Feb 26, 2018 at 12:15:28PM -0800, Jeremy McNicoll wrote:
>> On 2018-02-26 11:46 AM, Mika Westerberg wrote:
>>> On Mon, Feb 26, 2018 at 11:28:16AM -0800, Jeremy McNicoll wrote:
>>>> On 2018-02-26 5:38 AM, Mika Westerberg wrote:
>>>>> On Mon, Feb 26, 2018 at 12:20:29PM +0200, Mika Westerberg wrote:
>>>>>> On Thu, Feb 22, 2018 at 03:17:38PM -0800, Jeremy McNicoll wrote:
>>>>>>>> + if (pkg->link_info & ICM_LINK_INFO_REJECTED) {
>>>>>>>> + tb_info(tb, "switch at %u.%u was rejected by ICM firmware\n",
>>>>>>>> + link, depth);
>>>>>>>
>>>>>>> This kind of condition sounds more like an error instead of info.
>>>>>>> Please bump this up to tb_WARN/tb_warn ideally tb_err().
>>>>>>
>>>>>> No, this is not an error.
>>>>>
>>>>> To be more clear, it is totally fine to have the firmware to reject some
>>>>> devices. For example in case of the new usbonly security level the
>>>>> firmware rejects other devices but the first.
>>>>>
>>>>
>>>> Ok. Is that kind of information available to the kernel? What security
>>>> mode we are in?
>>>>
>>>> ie) if (LINK_REJECTED && !USB_SECURITY)
>>>> print "Error switch %u was rejected since its not usbonly"
>>>> endif
>>>>
>>>> I am sure something like that simplified pseudo code above would
>>>> be somewhat useful to users when debugging.
>>>
>>> That's why it is on info level so it goes to dmesg but does not scare
>>> the user :-)
>>>
>>
>> The point I am trying to make is that it would be nice to be able to
>> know WHY the link was rejected and not just that it was rejected.
>
> Fair enough. In practice (since we ask the firmware to accept any
> device) the only reason for rejection is that the topology limit is
> exceeded (too many devices in the chain).
>
> I'm thinking to change the message to something like:
>
> tb_info(tb, "switch at %u.%u was rejected by ICM firmware because topology limit exceeded\n",
> link, depth);
>
> And do the same for Titan Ridge in patch [18/18].
>
> Security level can be read directly from "security" sysfs attribute of
> the domain so that information does not need to be duplicated IMHO.
>
> Does that work for you?
>
Sounds good to me.
-jeremy
next prev parent reply other threads:[~2018-02-27 22:27 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-13 17:00 [PATCH 00/18] thunderbolt: Add support for Intel Titan Ridge Mika Westerberg
2018-02-13 17:00 ` [PATCH 01/18] thunderbolt: Resume control channel after hibernation image is created Mika Westerberg
2018-02-13 17:00 ` [PATCH 02/18] thunderbolt: Serialize PCIe tunnel creation with PCI rescan Mika Westerberg
2018-02-13 17:00 ` [PATCH 03/18] thunderbolt: Handle connecting device in place of host properly Mika Westerberg
2018-02-13 17:00 ` [PATCH 04/18] thunderbolt: Do not overwrite error code when domain adding fails Mika Westerberg
2018-02-13 17:00 ` [PATCH 05/18] thunderbolt: Wait a bit longer for root switch config space Mika Westerberg
2018-02-13 17:00 ` [PATCH 06/18] thunderbolt: Wait a bit longer for ICM to authenticate the active NVM Mika Westerberg
2018-02-13 17:21 ` Mario.Limonciello
2018-02-14 10:03 ` Mika Westerberg
2018-02-13 17:00 ` [PATCH 07/18] thunderbolt: Handle rejected Thunderbolt devices Mika Westerberg
2018-02-22 23:17 ` [07/18] " Jeremy McNicoll
2018-02-26 10:20 ` Mika Westerberg
2018-02-26 13:38 ` Mika Westerberg
2018-02-26 19:28 ` Jeremy McNicoll
2018-02-26 19:46 ` Mika Westerberg
2018-02-26 20:15 ` Jeremy McNicoll
2018-02-27 9:26 ` Mika Westerberg
2018-02-27 22:27 ` Jeremy McNicoll [this message]
2018-02-13 17:00 ` [PATCH 08/18] thunderbolt: Factor common ICM add and update operations out Mika Westerberg
2018-02-13 17:00 ` [PATCH 09/18] thunderbolt: Correct function name in kernel-doc comment Mika Westerberg
2018-02-13 17:00 ` [PATCH 10/18] thunderbolt: Add tb_switch_get() Mika Westerberg
2018-02-13 17:00 ` [PATCH 11/18] thunderbolt: Add tb_switch_find_by_route() Mika Westerberg
2018-02-13 17:00 ` [PATCH 12/18] thunderbolt: Add tb_xdomain_find_by_route() Mika Westerberg
2018-02-13 17:51 ` Andy Shevchenko
2018-02-14 10:25 ` Mika Westerberg
2018-02-13 17:00 ` [PATCH 13/18] thunderbolt: Add constant for approval timeout Mika Westerberg
2018-02-13 17:00 ` [PATCH 14/18] thunderbolt: Move driver ready handling to struct icm Mika Westerberg
2018-02-13 17:00 ` [PATCH 15/18] thunderbolt: Add 'boot' attribute for devices Mika Westerberg
2018-02-13 17:00 ` [PATCH 16/18] thunderbolt: Add support for preboot ACL Mika Westerberg
2018-02-13 18:19 ` Andy Shevchenko
2018-02-14 10:22 ` Mika Westerberg
2018-02-13 17:00 ` [PATCH 17/18] thunderbolt: Introduce USB only (SL4) security level Mika Westerberg
2018-02-14 0:29 ` Randy Dunlap
2018-02-14 10:09 ` Mika Westerberg
2018-02-13 17:00 ` [PATCH 18/18] thunderbolt: Add support for Intel Titan Ridge Mika Westerberg
2018-02-14 14:23 ` Andy Shevchenko
2018-02-14 14:28 ` Mika Westerberg
2018-02-14 14:29 ` Andy Shevchenko
2018-02-14 15:52 ` Mika Westerberg
2018-02-14 13:58 ` [PATCH 00/18] " Andy Shevchenko
2018-02-14 16:43 ` Mika Westerberg
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