From mboxrd@z Thu Jan 1 00:00:00 1970 From: jbrunet@baylibre.com (Jerome Brunet) Date: Tue, 19 Jun 2018 17:29:12 +0200 Subject: [PATCH] clk: meson-gxbb: set fclk_div2 as CLK_IS_CRITICAL In-Reply-To: <1528892771.2292.2.camel@baylibre.com> References: <1528892421-12180-1-git-send-email-narmstrong@baylibre.com> <1528892771.2292.2.camel@baylibre.com> Message-ID: <1529422152.28510.24.camel@baylibre.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 2018-06-13 at 14:26 +0200, Jerome Brunet wrote: > On Wed, 2018-06-13 at 14:20 +0200, Neil Armstrong wrote: > > On Amlogic Meson GXBB & GXL platforms, the SCPI Cortex-M4 Co-Processor > > seems to be dependent on the FCLK_DIV2 to be operationnal. > > > > The issue occured since v4.17-rc1 by freezing the kernel boot when > > the 'schedutil' cpufreq governor was selected as default : > > > > [ 12.071837] scpi_protocol scpi: SCP Protocol 0.0 Firmware 0.0.0 version > > domain-0 init dvfs: 4 > > [ 12.087757] hctosys: unable to open rtc device (rtc0) > > [ 12.087907] cfg80211: Loading compiled-in X.509 certificates for regulatory database > > [ 12.102241] cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7' > > > > But when disabling the MMC driver, the boot finished but cpufreq failed to > > change the CPU frequency : > > > > [ 12.153045] cpufreq: __target_index: Failed to change cpu frequency: -5 > > > > A bisect between v4.16 and v4.16-rc1 gave the 05f814402d61 commit to be > > the first bad commit. > > This commit added support for the missing clock gates before the fixed PLL > > fixed dividers (FCLK_DIVx) and the clock framework basically disabled > > all the unused fixed dividers, thus disabled a critical clock path for > > the SCPI Co-Processor. > > > > This patch simply sets the FCLK_DIV2 gate as critical to ensure > > nobody can disable it. > > > > Fixes: 05f814402d61 ("clk: meson: add fdiv clock gates") > > Signed-off-by: Neil Armstrong > > Good catch ! > We'll probably have to check the axg family as well SCPI is not enabled on AXG at this time. We'll deal with it when the time comes. patch applied. Thx