From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D46B52D607; Thu, 18 Jan 2024 18:27:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705602440; cv=none; b=CIAupL0fEb049DyiTAD86NX6I4PLPz7e/jwo2zW+cx0TvAGUsPf964Z+jHhAMwOx6Dm32S6OWFeM0EANUrBz4sy7EaqZsBxJulAEwIC9rqfaFXO3qZRkdDzlOGyfyK6zIwSmlpubslWzjnq1wRjiBs9oy2y6pWFcyZ48C1IX4UQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705602440; c=relaxed/simple; bh=2MOfPFz7G5ELeaymAprmqeqIr3xcUu1nA2k4jv5ebks=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cuegSm6MAc8qvEF5Q4n89walbUvsSogf2zmOGLZgGAYWMDQ3XKIVhhimIqu6nLIdfcXM+AObgfXIF1Utg6vn4C2w/O8wRnIO6uhBcuJwC8qqHsBOMX3sKmeZrZrgu7l3JA+mpqjtnBofoiJ43tJh9ihUl/7Hjt/dlbjcldMZtwQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 980B11042; Thu, 18 Jan 2024 10:28:02 -0800 (PST) Received: from pluto (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3C4943F766; Thu, 18 Jan 2024 10:27:15 -0800 (PST) Date: Thu, 18 Jan 2024 18:27:12 +0000 From: Cristian Marussi To: "Peng Fan (OSS)" Cc: sudeep.holla@arm.com, mturquette@baylibre.com, sboyd@kernel.org, linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, Peng Fan Subject: Re: [PATCH V3 2/2] clk: scmi: support state_ctrl_forbidden Message-ID: References: <20240115060203.813168-1-peng.fan@oss.nxp.com> <20240115060203.813168-2-peng.fan@oss.nxp.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240115060203.813168-2-peng.fan@oss.nxp.com> On Mon, Jan 15, 2024 at 02:02:03PM +0800, Peng Fan (OSS) wrote: > From: Peng Fan > > Some clocks may exported to linux, while those clocks are not allowed > to configure by Linux. For example: > > SYS_CLK1----- > \ > --MUX--->MMC1_CLK > / > SYS_CLK2----- > > MMC1 needs set parent, so SYS_CLK1 and SYS_CLK2 are exported to Linux, > then the clk propagation will touch SYS_CLK1 or SYS_CLK2. > So we need bypass the failure for SYS_CLK1 or SYS_CLK2 when enable > the clock of MMC1. > Hi, so this looks good to me and apparently (as noted) the CLK framework is OK with a driver swallowing the -EACCESS when a clock is immutable, BUT at the end of the day do we even need to try this SCMI call and hide the failure in case of immutable clocks ? I mean, what if we just dont provide any callback for enable/disable...I can see plenty of drivers not providing those callbacks ? Maybe this is probably more of a question for Stephen... IOW what about doing something like below...does it make any difference in your setup ? works fine in my emulated env (Note that last snippet in clk_gate_restore_context() is probably a fix that needs to be added anyway by looking at the code in clk.c) Thanks, Cristian --->8---- diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c index 5327e0547741..a669a2f2f78b 100644 --- a/drivers/clk/clk-scmi.c +++ b/drivers/clk/clk-scmi.c @@ -121,11 +121,7 @@ static int scmi_clk_enable(struct clk_hw *hw) struct scmi_clk *clk = to_scmi_clk(hw); int ret; - ret = scmi_proto_clk_ops->enable(clk->ph, clk->id, NOT_ATOMIC); - if (ret == -EACCES && clk->info->state_ctrl_forbidden) - return 0; - - return ret; + return scmi_proto_clk_ops->enable(clk->ph, clk->id, NOT_ATOMIC); } static void scmi_clk_disable(struct clk_hw *hw) @@ -140,11 +136,7 @@ static int scmi_clk_atomic_enable(struct clk_hw *hw) struct scmi_clk *clk = to_scmi_clk(hw); int ret; - ret = scmi_proto_clk_ops->enable(clk->ph, clk->id, ATOMIC); - if (ret == -EACCES && clk->info->state_ctrl_forbidden) - return 0; - - return ret; + return scmi_proto_clk_ops->enable(clk->ph, clk->id, ATOMIC); } static void scmi_clk_atomic_disable(struct clk_hw *hw) @@ -204,6 +196,15 @@ static const struct clk_ops scmi_atomic_clk_ops = { .determine_rate = scmi_clk_determine_rate, }; +static const struct clk_ops scmi_no_state_ctrl_clk_ops = { + .recalc_rate = scmi_clk_recalc_rate, + .round_rate = scmi_clk_round_rate, + .set_rate = scmi_clk_set_rate, + .set_parent = scmi_clk_set_parent, + .get_parent = scmi_clk_get_parent, + .determine_rate = scmi_clk_determine_rate, +}; + static int scmi_clk_ops_init(struct device *dev, struct scmi_clk *sclk, const struct clk_ops *scmi_ops) { @@ -300,8 +301,10 @@ static int scmi_clocks_probe(struct scmi_device *sdev) * specify (or support) an enable_latency associated with a * clock, we default to use atomic operations mode. */ - if (is_atomic && - sclk->info->enable_latency <= atomic_threshold) + if (sclk->info->state_ctrl_forbidden) + scmi_ops = &scmi_no_state_ctrl_clk_ops; + else if (is_atomic && + sclk->info->enable_latency <= atomic_threshold) scmi_ops = &scmi_atomic_clk_ops; else scmi_ops = &scmi_clk_ops; diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index f0940af485a5..79b90a8099d7 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1200,9 +1200,11 @@ void clk_gate_restore_context(struct clk_hw *hw) struct clk_core *core = hw->core; if (core->enable_count) - core->ops->enable(hw); + if (core->ops->enable) + core->ops->enable(hw); else - core->ops->disable(hw); + if (core->ops->disable) + core->ops->disable(hw); } EXPORT_SYMBOL_GPL(clk_gate_restore_context); ---8<--- > Signed-off-by: Peng Fan > --- > > V3: > Add check in atomic enable > > V2: > New. Take Cristian's suggestion > > drivers/clk/clk-scmi.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c > index 8cbe24789c24..5327e0547741 100644 > --- a/drivers/clk/clk-scmi.c > +++ b/drivers/clk/clk-scmi.c > @@ -119,8 +119,13 @@ static int scmi_clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *r > static int scmi_clk_enable(struct clk_hw *hw) > { > struct scmi_clk *clk = to_scmi_clk(hw); > + int ret; > + > + ret = scmi_proto_clk_ops->enable(clk->ph, clk->id, NOT_ATOMIC); > + if (ret == -EACCES && clk->info->state_ctrl_forbidden) > + return 0; > > - return scmi_proto_clk_ops->enable(clk->ph, clk->id, NOT_ATOMIC); > + return ret; > } > > static void scmi_clk_disable(struct clk_hw *hw) > @@ -133,8 +138,13 @@ static void scmi_clk_disable(struct clk_hw *hw) > static int scmi_clk_atomic_enable(struct clk_hw *hw) > { > struct scmi_clk *clk = to_scmi_clk(hw); > + int ret; > + > + ret = scmi_proto_clk_ops->enable(clk->ph, clk->id, ATOMIC); > + if (ret == -EACCES && clk->info->state_ctrl_forbidden) > + return 0; > > - return scmi_proto_clk_ops->enable(clk->ph, clk->id, ATOMIC); > + return ret; > } > > static void scmi_clk_atomic_disable(struct clk_hw *hw) > -- > 2.37.1 >