From patchwork Thu Mar 7 02:03:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Xiwen via B4 Relay X-Patchwork-Id: 13584965 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 0684529B0; Thu, 7 Mar 2024 02:03:51 +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=1709777032; cv=none; b=tMLg48ZPKZ3aoULYX6wASoHqrxAP/+e2ZSWXgLkQilhtOD/wD7gdp8KQGPoRD+wSWFq8xBpiMQJSGSwE9l4yBUZXeGdSDb0QJ5eU6N1CZ3Tk13XHXbfescyNv9XxkQQlLW49QYV8TRmsXeIWL/FdRSJjxCaVcxguKUAUVbMkn1M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709777032; c=relaxed/simple; bh=Cl8dTmlc9duSd7n28lik+iwh3pfH6s7fs5pow85J+Dw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=o4lPNWsTSupQomIR+AiyX/MFOf+Wx2JwiIJhYLPSlQpUl3KMUAgqr+W0AgQ37dbz94O6Zb6Ql7ITKNQ785YgF4429ivOtvC7cDl/FHnJlOF8tZ5hNH18YRykvRv20jgezwWrnTGoqC4kDroY2pnM+vtWi7neXG9SwY38sgNdvoM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IJVDjvMo; 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="IJVDjvMo" Received: by smtp.kernel.org (Postfix) with ESMTPS id 561E0C433C7; Thu, 7 Mar 2024 02:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709777031; bh=Cl8dTmlc9duSd7n28lik+iwh3pfH6s7fs5pow85J+Dw=; h=From:Date:Subject:To:Cc:Reply-To:From; b=IJVDjvMo9/wrge++fpaDouU/gfUKJz1mPmlQCgxRJWC0Ewm0uST1x8OZCLwSlYqex C5jj3gRifVQYWQADzKCviEgPT8I0j0q1Ivk46kvt/o0EIH6GFt7vRahZo6BZI0mPBo 3yI0B4rG1PBdqCbZwNDZaOQI1T4T4xYVsc3IHumI60y3Gv3AtxI5i9v2pqhn+tvMjD I5zAi78ZBgucsFenSj/tgtcU8NgDpYy5L6m+SqnANiVIAjeP0dEiYl4RrsZKK1DcBD KHVBItkhH5DLHdQkjjq9Se0o1QK7xxW9US0SffLLSg1wl7V8VWOGfOlfiqW54Tx4sI mgJFtCn4ulEsw== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3972BC54E41; Thu, 7 Mar 2024 02:03:51 +0000 (UTC) From: Yang Xiwen via B4 Relay Date: Thu, 07 Mar 2024 10:03:50 +0800 Subject: [PATCH v3] clk: set initial best mux parent to current parent with CLK_MUX_ROUND_CLOSEST Precedence: bulk X-Mailing-List: linux-clk@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240307-mux-v3-1-0885fc1ab2c9@outlook.com> X-B4-Tracking: v=1; b=H4sIAIUg6WUC/1WM0Q6CIBhGX8Vx3d/gBy276j1aFyCQrJQGymzOd w/tonl5vn3nzCSa4Ewkl2ImwSQXne8z8ENBmlb2DwNOZyZIUVBkJXTjBJVWZ8VPTJQ1Jfn5Dsa 6aavc7plbFwcfPls0sXXd+4kBA6MUWiU506K++nF4ef88Nr4jayHh3+K0+lkIFGqUpZWiYlbj3 lqW5QsHS1sRzgAAAA== To: Michael Turquette , Stephen Boyd Cc: Maxime Ripard , linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, Yang Xiwen X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=ed25519-sha256; t=1709777030; l=1992; i=forbidden405@outlook.com; s=20230724; h=from:subject:message-id; bh=+mzOqRRpetTLywKtq+naXweDz2ih9wEm/mCbtZc7rOw=; b=q+iZF6EtDER3d5gAVZq04xD7GVCQQOVDTZPRm4F+aCBXhuLGOt+Y78TQ2fuynzckogHnLL6vD XzZ5kgSoK0xCpTlzgt55ANodTR7HaH4eNJg3XL7hLANVkNYw5P2M0Cp X-Developer-Key: i=forbidden405@outlook.com; a=ed25519; pk=qOD5jhp891/Xzc+H/PZ8LWVSWE3O/XCQnAg+5vdU2IU= X-Endpoint-Received: by B4 Relay for forbidden405@outlook.com/20230724 with auth_id=67 X-Original-From: Yang Xiwen Reply-To: From: Yang Xiwen Originally, the initial clock rate is hardcoded to 0, this can lead to some problem when setting a very small rate with CLK_MUX_ROUND_CLOSEST. For example, if the lowest possible rate provided by the mux is 1000Hz, setting a rate below 500Hz will fail, because no clock can provide a better rate than the non-existant 0Hz. But it should succeed with 1000Hz being set. Setting the initial best parent to current parent could solve this bug. Signed-off-by: Yang Xiwen --- This is actually a v2 of [1]. It's tested in a mmc host driver. [1]: https://lore.kernel.org/linux-clk/20230421-clk-v3-1-9ff79e7e7fed@outlook.com/ --- Changes in v3: - remove the fix for clk_test.c - limit the fix to CLK_MUX_ROUND_CLOSEST - Link to v2: https://lore.kernel.org/r/20240306-mux-v2-0-92a5fa461fd2@outlook.com Changes in v2: - cover letter: remove statements about unittest - add fix for clk_test.c - s/privide/provide - Cc Maxime All suggested by Stephan Boyd - Link to v1: https://lore.kernel.org/r/20240215-mux-v1-1-ebb2fba31d49@outlook.com --- drivers/clk/clk.c | 6 ++++++ 1 file changed, 6 insertions(+) --- base-commit: 90d35da658da8cff0d4ecbb5113f5fac9d00eb72 change-id: 20240215-mux-6db8b3714590 Best regards, diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2253c154a824..74dd61f7269f 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -647,6 +647,12 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw, if (core->flags & CLK_SET_RATE_NO_REPARENT) return clk_core_determine_rate_no_reparent(hw, req); + /* if MUX_ROUND_CLOSEST is set, set the initial best parent to current parent */ + if (flags & CLK_MUX_ROUND_CLOSEST) { + best_parent = core->parent; + best = clk_core_get_rate_nolock(core); + } + /* find the parent that can provide the fastest rate <= rate */ num_parents = core->num_parents; for (i = 0; i < num_parents; i++) {