From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH] ACPI/PPTT: Handle architecturally unknown cache types Date: Wed, 12 Sep 2018 16:38:41 +0100 Message-ID: <2873c62f-1bf9-5aa0-b3a2-07980ef61d35@arm.com> References: <1536694334-5811-1-git-send-email-jhugo@codeaurora.org> <98e2e6fa-7256-b5ac-7d2e-42c858c6e57c@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Jeffrey Hugo , Jeremy Linton , rjw@rjwysocki.net, linux-acpi@vger.kernel.org Cc: Sudeep Holla , linux-kernel@vger.kernel.org, vkilari@codeaurora.org List-Id: linux-acpi@vger.kernel.org On 12/09/18 16:27, Sudeep Holla wrote: > > > On 12/09/18 15:41, Jeffrey Hugo wrote: [...] >> >> Correct.  However, what if you have a NOCACHE (not architecturally >> specified), that is fully described in PPTT, as a non-unified cache >> (data only)?  Unlikely?  Maybe.  Still seem possible though, therefore I >> feel this assumption is suspect. >> > > Yes, we have other issues if the architecturally not specified cache is > not unified irrespective of what PPTT says. So we may need to review and > see if that assumption is removed everywhere. > > Until then why can't a simple change fix the issue you have: > > -->8 > > diff --git i/drivers/acpi/pptt.c w/drivers/acpi/pptt.c > index d1e26cb599bf..f74131201f5e 100644 > --- i/drivers/acpi/pptt.c > +++ w/drivers/acpi/pptt.c > @@ -406,7 +406,8 @@ static void update_cache_properties(struct cacheinfo > *this_leaf, > * update the cache type as well. > */ > if (this_leaf->type == CACHE_TYPE_NOCACHE && > - valid_flags == PPTT_CHECKED_ATTRIBUTES) > + (valid_flags == PPTT_CHECKED_ATTRIBUTES || > + found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)) Looking at this again, if we are supporting just presence of cache type and size(may be), then we can drop the whole valid_flags thing here. > this_leaf->type = CACHE_TYPE_UNIFIED; > } > -- Regards, Sudeep