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Date:   Wed, 13 Jan 2021 11:48:24 +0000
From:   Marc Zyngier <maz@kernel.org>
To:     Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc:     Saravana Kannan <saravanak@google.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>, kernel-team@android.com,
        linux-kernel@vger.kernel.org,
        Jisheng Zhang <Jisheng.Zhang@synaptics.com>,
        Kevin Hilman <khilman@baylibre.com>,
        John Stultz <john.stultz@linaro.org>
Subject: Re: [PATCH v1 0/5] Enable fw_devlink=on by default
In-Reply-To: <712cb4237f1dbb8d1104736e20713ba457444650.camel@suse.de>
References: <20201218031703.3053753-1-saravanak@google.com>
 <712cb4237f1dbb8d1104736e20713ba457444650.camel@suse.de>
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On 2021-01-13 11:44, Nicolas Saenz Julienne wrote:
> On Thu, 2020-12-17 at 19:16 -0800, Saravana Kannan wrote:
>> As discussed in LPC 2020, cyclic dependencies in firmware that 
>> couldn't
>> be broken using logic was one of the last remaining reasons
>> fw_devlink=on couldn't be set by default.
>> 
>> This series changes fw_devlink so that when a cyclic dependency is 
>> found
>> in firmware, the links between those devices fallback to permissive 
>> mode
>> behavior. This way, the rest of the system still benefits from
>> fw_devlink, but the ambiguous cases fallback to permissive mode.
>> 
>> Setting fw_devlink=on by default brings a bunch of benefits 
>> (currently,
>> only for systems with device tree firmware):
>> * Significantly cuts down deferred probes.
>> * Device probe is effectively attempted in graph order.
>> * Makes it much easier to load drivers as modules without having to
>>   worry about functional dependencies between modules (depmod is still
>>   needed for symbol dependencies).
> 
> FWIW I don't see any issues with this on Raspberry Pi 4 :).

Keep bragging! ;-)

         M.
-- 
Jazz is not dead. It just smells funny...