From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2042A1DC746; Tue, 3 Sep 2024 20:02:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725393746; cv=none; b=Gl4w/6Gn1VIoZS6j/yz7r40/AIc7Jz/2Xp7JoZyx2hGxWF2CMjeg7Wz/dERbVgfpHxNus9StKw6RmKsMoZWITZfacBq90p9J3skSJaL4jvP+KDCYjDeyL0Z56H0E776RrzX45BQrodUr5eKQFQrC2D4iO4EvfCaa8qVUqHWyEZA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725393746; c=relaxed/simple; bh=/BbWsnQvQojQuHvQGPzYTHEKobUCT3g2HuvksNY8isI=; h=Message-ID:Content-Type:MIME-Version:In-Reply-To:References: Subject:From:Cc:To:Date; b=p8LIvSpyQ7DxKtIzjO2qQZ0MNP+j88IsHktmszxIlFfFtZFqS34fm5SkjzIlRS5p/zZBKZ67PYg4OzgIrIY7G47IvKVYM7Gz9sq2AhVC4GiW/w3ax2eD43pPV4A1ly9cQL82i/ZpQtbQRrBQG2QiPiMNsPOhycLDGYDvGONKazw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ANJ8Zw4I; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ANJ8Zw4I" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D469C4CEC4; Tue, 3 Sep 2024 20:02:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725393745; bh=/BbWsnQvQojQuHvQGPzYTHEKobUCT3g2HuvksNY8isI=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=ANJ8Zw4IEXajgPFCvxDtB6mwuKeSOy32UjP7xeeAOxhSeuZeniEMq4hLZJBXO52kc +KWgE4pr5DkdcNL0gBonnVnGQme6IR+1y8gH5wmGk6+U/0u7fWdRA0KwvSyN+TYyvx Q7tRWJlAXR1YUpL/QG18O3w0J71/cGYfgSBDHRvEu9zlYHJa12g2+n/5HRHyAwCnV/ pDdrgeW8fsR7J2Bzuic1cEOTT8iB+RPSj3mNBbnVt1nwlzdfPbUQC30vjq4UvW70se EgMVU0naFFt+PMSqnUZMG4fPoAaoJPOzfQUPZ01YypDmos0TjAZ0c3JrYggwK2D/r/ hySR3buOJqGlQ== Message-ID: <59429303c8158b146b24d14f4869fcd5.sboyd@kernel.org> Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20240902070830.8535-1-johan+linaro@kernel.org> References: <20240902070830.8535-1-johan+linaro@kernel.org> Subject: Re: [PATCH] clk: qcom: gcc-sc8280xp: don't use parking clk_ops for QUPs From: Stephen Boyd Cc: Bjorn Andersson , Michael Turquette , linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold To: Johan Hovold Date: Tue, 03 Sep 2024 13:02:23 -0700 User-Agent: alot/0.10 Quoting Johan Hovold (2024-09-02 00:08:30) > A recent change started parking the RCG at an always on parent during > registration, something which specifically breaks handover from an early > serial console. >=20 > Quoting Stephen Boyd who fixed this issue for SM8550 [1]: >=20 > The QUPs aren't shared in a way that requires parking the RCG at > an always on parent in case some other entity turns on the clk. > The hardware is capable of setting a new frequency itself with > the DFS mode, so parking is unnecessary. Furthermore, there > aren't any GDSCs for these devices, so there isn't a possibility > of the GDSC turning on the clks for housekeeping purposes. >=20 > This wasn't a problem to mark these clks shared until we started > parking shared RCGs at clk registration time in commit > 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration"). > Parking at init is actually harmful to the UART when earlycon is > used. If the device is pumping out data while the frequency > changes you'll see garbage on the serial console until the > driver can probe and actually set a proper frequency. >=20 > Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration") > Fixes: d65d005f9a6c ("clk: qcom: add sc8280xp GCC driver") > Link: https://lore.kernel.org/all/20240819233628.2074654-2-swboyd@chromiu= m.org/ [1] > Signed-off-by: Johan Hovold > --- Applied to clk-fixes