Linux-Clk Archive on
 help / color / Atom feed
From: Stephen Boyd <>
To: Michael Turquette <>,
	Stephen Boyd <>
	Rajendra Nayak <>
Subject: [PATCH] clk: qcom: Don't overwrite 'cfg' in clk_rcg2_dfs_populate_freq()
Date: Tue, 28 Jan 2020 11:33:29 -0800
Message-ID: <> (raw)

The DFS frequency table logic overwrites 'cfg' while detecting the
parent clk and then later on in clk_rcg2_dfs_populate_freq() we use that
same variable to figure out the mode of the clk, either MND or not. Add
a new variable to hold the parent clk bit so that 'cfg' is left
untouched for use later.

This fixes problems in detecting the supported frequencies for any clks
in DFS mode.

Fixes: cc4f6944d0e3 ("clk: qcom: Add support for RCG to register for DFS")
Reported-by: Rajendra Nayak <>
Signed-off-by: Stephen Boyd <>
 drivers/clk/qcom/clk-rcg2.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index da045b200def..973ecf4f6bc5 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -953,7 +953,7 @@ static void clk_rcg2_dfs_populate_freq(struct clk_hw *hw, unsigned int l,
 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
 	struct clk_hw *p;
 	unsigned long prate = 0;
-	u32 val, mask, cfg, mode;
+	u32 val, mask, cfg, mode, src;
 	int i, num_parents;
 	regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + SE_PERF_DFSR(l), &cfg);
@@ -963,12 +963,12 @@ static void clk_rcg2_dfs_populate_freq(struct clk_hw *hw, unsigned int l,
 	if (cfg & mask)
 		f->pre_div = cfg & mask;
-	cfg &= CFG_SRC_SEL_MASK;
-	cfg >>= CFG_SRC_SEL_SHIFT;
+	src = cfg & CFG_SRC_SEL_MASK;
+	src >>= CFG_SRC_SEL_SHIFT;
 	num_parents = clk_hw_get_num_parents(hw);
 	for (i = 0; i < num_parents; i++) {
-		if (cfg == rcg->parent_map[i].cfg) {
+		if (src == rcg->parent_map[i].cfg) {
 			f->src = rcg->parent_map[i].src;
 			p = clk_hw_get_parent_by_index(&rcg->clkr.hw, i);
 			prate = clk_hw_get_rate(p);
Sent by a computer, using git, on the internet

             reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-28 19:33 Stephen Boyd [this message]
2020-01-29  3:21 ` Rajendra Nayak
2020-02-03 19:19 ` Stephen Boyd

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Clk Archive on

Archives are clonable:
	git clone --mirror linux-clk/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-clk linux-clk/ \
	public-inbox-index linux-clk

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone