Re: [PATCH] interconnect: Restore sync state by ignoring ipa-virt in provider count

From: Nathan Chancellor <nathan@kernel.org>
To: Stephen Boyd <swboyd@chromium.org>
Cc: Georgi Djakov <djakov@kernel.org>,
	linux-kernel@vger.kernel.org, patches@lists.linux.dev,
	linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Doug Anderson <dianders@chromium.org>,
	Alex Elder <elder@linaro.org>, Taniya Das <quic_tdas@quicinc.com>,
	Mike Tipton <quic_mdtipton@quicinc.com>
Subject: Re: [PATCH] interconnect: Restore sync state by ignoring ipa-virt in provider count
Date: Mon, 2 May 2022 08:18:24 -0700	[thread overview]
Message-ID: <Ym/2QJeGHDoZSw8o@dev-arch.thelio-3990X> (raw)
In-Reply-To: <20220427013226.341209-1-swboyd@chromium.org>

Hi Stephen,

On Tue, Apr 26, 2022 at 06:32:26PM -0700, Stephen Boyd wrote:
> Ignore compatible strings for the IPA virt drivers that were removed in
> commits 2fb251c26560 ("interconnect: qcom: sdx55: Drop IP0
> interconnects") and 2f3724930eb4 ("interconnect: qcom: sc7180: Drop IP0
> interconnects") so that the sync state logic can kick in again.
> Otherwise all the interconnects in the system will stay pegged at max
> speeds because 'providers_count' is always going to be one larger than
> the number of drivers that will ever probe on sc7180 or sdx55. This
> fixes suspend on sc7180 and sdx55 devices when you don't have a
> devicetree patch to remove the ipa-virt compatible node.
> 
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Doug Anderson <dianders@chromium.org>
> Cc: Alex Elder <elder@linaro.org>
> Cc: Taniya Das <quic_tdas@quicinc.com>
> Cc: Mike Tipton <quic_mdtipton@quicinc.com>
> Fixes: 2fb251c26560 ("interconnect: qcom: sdx55: Drop IP0 interconnects")
> Fixes: 2f3724930eb4 ("interconnect: qcom: sc7180: Drop IP0 interconnects")
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>

This patch as commit ad3cc2f05fda ("interconnect: Restore sync state by
ignoring ipa-virt in provider count") in -next causes the following
build warning when CONFIG_OF is disabled because of_match_node is just
NULL:

drivers/interconnect/core.c:1090:28: warning: unused variable 'ignore_list' [-Wunused-variable]
        const struct of_device_id ignore_list[] = {
                                  ^
1 warning generated.

Should it just be marked as __maybe_unused or is there a different fix
that would be more appropriate?

Cheers,
Nathan