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[90.63.244.31]) by smtp.gmail.com with ESMTPSA id l10-20020a5d560a000000b0021b9270de3csm20415757wrv.10.2022.06.30.05.39.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Jun 2022 05:39:51 -0700 (PDT) References: <20220628141038.168383-1-windhl@126.com> User-agent: mu4e 1.6.10; emacs 27.1 From: Jerome Brunet To: narmstrong@baylibre.com, mturquette@baylibre.com, sboyd@kernel.org, khilman@baylibre.com, martin.blumenstingl@googlemail.co, linux-clk@vger.kernel.org, linux-amlogic@lists.infradead.org, windhl@126.com Subject: Re: [PATCH v2] clk: meson: Hold reference returned by of_get_parent() Date: Thu, 30 Jun 2022 14:29:30 +0200 In-reply-to: <20220628141038.168383-1-windhl@126.com> Message-ID: <1jbkua1g15.fsf@starbuckisacylon.baylibre.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On Tue 28 Jun 2022 at 22:10, Liang He wrote: > We should hold the reference returned by of_get_parent() and use it > to call of_node_put() for refcount balance. > > Fixes: 88e2da81241e ("clk: meson: aoclk: refactor common code into dedicated file") > Fixes: 6682bd4d443f ("clk: meson: factorise meson64 peripheral clock controller drivers") > Fixes: bb6eddd1d28c ("clk: meson: meson8b: use the HHI syscon if available") Fixing different commits with a single one is not going to make stable backport easy. I would prefer if you could submit a patch for each fixes/driver. Not blocking for a v3 but worth considering after looking at the number of drivers making the same mistake: * make a syscon function to deal with of_get_parent(), syscon_node_to_regmap() and of_node_put() instead of duplicating the code everywhere. * Propose a coccinelle script to detect/fix this in the future > > Signed-off-by: Liang He > --- > changelog: > > v2: change the name of 'tp', change the title format, keep reverse christmas tree > v1: hold reference returned by of_get_parent() > > v1-link: https://lore.kernel.org/all/20220624102719.4166125-1-windhl@126.com/ > > Patched files have been compiled test in 5.19rc2. > > > drivers/clk/meson/meson-aoclk.c | 5 ++++- > drivers/clk/meson/meson-eeclk.c | 5 ++++- > drivers/clk/meson/meson8b.c | 5 ++++- > 3 files changed, 12 insertions(+), 3 deletions(-) > > diff --git a/drivers/clk/meson/meson-aoclk.c b/drivers/clk/meson/meson-aoclk.c > index 27cd2c1f3f61..434cd8f9de82 100644 > --- a/drivers/clk/meson/meson-aoclk.c > +++ b/drivers/clk/meson/meson-aoclk.c > @@ -38,6 +38,7 @@ int meson_aoclkc_probe(struct platform_device *pdev) > struct meson_aoclk_reset_controller *rstc; > struct meson_aoclk_data *data; > struct device *dev = &pdev->dev; > + struct device_node *np; > struct regmap *regmap; > int ret, clkid; > > @@ -49,7 +50,9 @@ int meson_aoclkc_probe(struct platform_device *pdev) > if (!rstc) > return -ENOMEM; > > - regmap = syscon_node_to_regmap(of_get_parent(dev->of_node)); > + np = of_get_parent(dev->of_node); > + regmap = syscon_node_to_regmap(np); > + of_node_put(np); > if (IS_ERR(regmap)) { > dev_err(dev, "failed to get regmap\n"); > return PTR_ERR(regmap); > diff --git a/drivers/clk/meson/meson-eeclk.c b/drivers/clk/meson/meson-eeclk.c > index 8d5a5dab955a..0e5e6b57eb20 100644 > --- a/drivers/clk/meson/meson-eeclk.c > +++ b/drivers/clk/meson/meson-eeclk.c > @@ -18,6 +18,7 @@ int meson_eeclkc_probe(struct platform_device *pdev) > { > const struct meson_eeclkc_data *data; > struct device *dev = &pdev->dev; > + struct device_node *np; > struct regmap *map; > int ret, i; > > @@ -26,7 +27,9 @@ int meson_eeclkc_probe(struct platform_device *pdev) > return -EINVAL; > > /* Get the hhi system controller node */ > - map = syscon_node_to_regmap(of_get_parent(dev->of_node)); > + np = of_get_parent(dev->of_node); > + map = syscon_node_to_regmap(np); > + of_node_put(np); > if (IS_ERR(map)) { > dev_err(dev, > "failed to get HHI regmap\n"); > diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c > index 8f3b7a94a667..827e78fb16a8 100644 > --- a/drivers/clk/meson/meson8b.c > +++ b/drivers/clk/meson/meson8b.c > @@ -3792,12 +3792,15 @@ static void __init meson8b_clkc_init_common(struct device_node *np, > struct clk_hw_onecell_data *clk_hw_onecell_data) > { > struct meson8b_clk_reset *rstc; > + struct device_node *parent_np; > const char *notifier_clk_name; > struct clk *notifier_clk; > struct regmap *map; > int i, ret; > > - map = syscon_node_to_regmap(of_get_parent(np)); > + parent_np = of_get_parent(np); > + map = syscon_node_to_regmap(parent_np); > + of_node_put(parent_np); > if (IS_ERR(map)) { > pr_err("failed to get HHI regmap - Trying obsolete regs\n"); > return;