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[73.214.169.22]) by smtp.gmail.com with ESMTPSA id f10-20020a81414a000000b00545a08184desm3687792ywk.110.2023.04.11.12.22.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Apr 2023 12:22:03 -0700 (PDT) From: Brian Masney To: corbet@lwn.net, sboyd@kernel.org Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, mturquette@baylibre.com, linux-doc@vger.kernel.org Subject: [PATCH] docs: clk: add documentation to log which clocks have been disabled Date: Tue, 11 Apr 2023 15:21:53 -0400 Message-Id: <20230411192153.289688-1-bmasney@redhat.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org The existing clk documentation has a section that talks about the clk_ignore_unused kernel parameter. Add additional documentation that describes how to log which clocks the kernel disables on bootup. This will log messages like the following to the console on bootup: [ 1.268115] clk: Disabling unused clocks [ 1.272167] clk_disable: gcc_usb_clkref_en [ 1.276389] clk_disable: gcc_usb30_sec_sleep_clk [ 1.281131] clk_disable: gcc_usb30_prim_sleep_clk ... Signed-off-by: Brian Masney --- Documentation/driver-api/clk.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/driver-api/clk.rst b/Documentation/driver-api/clk.rst index 3cad45d14187..2199c0042e75 100644 --- a/Documentation/driver-api/clk.rst +++ b/Documentation/driver-api/clk.rst @@ -258,6 +258,11 @@ clocks properly but rely on them being on from the bootloader, bypassing the disabling means that the driver will remain functional while the issues are sorted out. +You can see which clocks have been disabled by booting your kernel with these +parameters: + + tp_printk trace_event=clk:clk_disable + To bypass this disabling, include "clk_ignore_unused" in the bootargs to the kernel.