| Message ID | 20170312213406.20987-1-gmbnomis@gmail.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Boris Brezillon |
| Headers | show |
Hello Simon, On Sun, Mar 12, 2017 at 10:34:06PM +0100, Simon Baatz wrote: > The clk handling in orion_nand.c had two problems: > > - In the probe function, clk_put() was called for an enabled clock, > which violates the API (see documentation for clk_put() in > include/linux/clk.h) > > - In the error path of the probe function, clk_put() could be called > twice for the same clock. > > In order to clean this up, use the managed function devm_clk_get() and > store the pointer to the clk in the driver data. > > Fixes: baffab28b13120694fa3ebab08d3e99667a851d2 ('ARM: Orion: fix driver probe error handling with respect to clk') > Cc: <stable@vger.kernel.org> # v4.5+ > Signed-off-by: Simon Baatz <gmbnomis@gmail.com> > --- > drivers/mtd/nand/orion_nand.c | 42 +++++++++++++++++++++--------------------- > 1 file changed, 21 insertions(+), 21 deletions(-) > > diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c > index 4a91c5d000be..b355aa738fae 100644 > --- a/drivers/mtd/nand/orion_nand.c > +++ b/drivers/mtd/nand/orion_nand.c > @@ -23,6 +23,11 @@ > #include <asm/sizes.h> > #include <linux/platform_data/mtd-orion_nand.h> > > +struct orion_nand_info { > + struct nand_chip chip; > + struct clk *clk; > +}; > + > static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) > { > struct nand_chip *nc = mtd_to_nand(mtd); > @@ -75,20 +80,21 @@ static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) > > static int __init orion_nand_probe(struct platform_device *pdev) > { > + struct orion_nand_info *info; > struct mtd_info *mtd; > struct nand_chip *nc; > struct orion_nand_data *board; > struct resource *res; > - struct clk *clk; > void __iomem *io_base; > int ret = 0; > u32 val = 0; > > - nc = devm_kzalloc(&pdev->dev, > - sizeof(struct nand_chip), > + info = devm_kzalloc(&pdev->dev, > + sizeof(struct orion_nand_info), > GFP_KERNEL); > - if (!nc) > + if (!info) > return -ENOMEM; > + nc = &info->chip; > mtd = nand_to_mtd(nc); > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > @@ -145,15 +151,13 @@ static int __init orion_nand_probe(struct platform_device *pdev) > if (board->dev_ready) > nc->dev_ready = board->dev_ready; > > - platform_set_drvdata(pdev, mtd); > + platform_set_drvdata(pdev, info); > > /* Not all platforms can gate the clock, so it is not > an error if the clock does not exists. */ > - clk = clk_get(&pdev->dev, NULL); > - if (!IS_ERR(clk)) { > - clk_prepare_enable(clk); > - clk_put(clk); > - } > + info->clk = devm_clk_get(&pdev->dev, NULL); > + if (!IS_ERR(info->clk)) > + clk_prepare_enable(info->clk); Orthogonal to your patch I suggest: - info->clk = devm_clk_get(&pdev->dev, NULL); - if (!IS_ERR(info->clk)) - clk_prepare_enable(info->clk); + info->clk = devm_clk_get_optional(&pdev->dev, NULL); + if (IS_ERR(info->clk)) { + ret = PTR_ERR(info->clk); + if (ret != -EPROBE_DEFER) + dev_err(...); + return ret; + } to correct error handling. (I didn't check if a plain return is right here, and also other users of info->clk need adaption.) Best regards Uwe
Hello Uwe, On Mon, Mar 13, 2017 at 08:12:41AM +0100, Uwe Kleine-K?nig wrote: > Hello Simon, > > On Sun, Mar 12, 2017 at 10:34:06PM +0100, Simon Baatz wrote: > > The clk handling in orion_nand.c had two problems: > > > > - In the probe function, clk_put() was called for an enabled clock, > > which violates the API (see documentation for clk_put() in > > include/linux/clk.h) > > > > - In the error path of the probe function, clk_put() could be called > > twice for the same clock. > > > > In order to clean this up, use the managed function devm_clk_get() and > > store the pointer to the clk in the driver data. ... > > /* Not all platforms can gate the clock, so it is not > > an error if the clock does not exists. */ > > - clk = clk_get(&pdev->dev, NULL); > > - if (!IS_ERR(clk)) { > > - clk_prepare_enable(clk); > > - clk_put(clk); > > - } > > + info->clk = devm_clk_get(&pdev->dev, NULL); > > + if (!IS_ERR(info->clk)) > > + clk_prepare_enable(info->clk); > > Orthogonal to your patch I suggest: > > - info->clk = devm_clk_get(&pdev->dev, NULL); > - if (!IS_ERR(info->clk)) > - clk_prepare_enable(info->clk); > + info->clk = devm_clk_get_optional(&pdev->dev, NULL); > + if (IS_ERR(info->clk)) { > + ret = PTR_ERR(info->clk); > + if (ret != -EPROBE_DEFER) > + dev_err(...); > + return ret; > + } > > to correct error handling. > (I didn't check if a plain return is right here, and also other users of > info->clk need adaption.) Nice! However, I can't find a devm_clk_get_optional() anywhere(?) Is it in some upcoming patch? - Simon
Hello Simon, On Mon, Mar 13, 2017 at 09:43:44PM +0100, Simon Baatz wrote: > Hello Uwe, > > On Mon, Mar 13, 2017 at 08:12:41AM +0100, Uwe Kleine-K?nig wrote: > > Hello Simon, > > > > On Sun, Mar 12, 2017 at 10:34:06PM +0100, Simon Baatz wrote: > > > The clk handling in orion_nand.c had two problems: > > > > > > - In the probe function, clk_put() was called for an enabled clock, > > > which violates the API (see documentation for clk_put() in > > > include/linux/clk.h) > > > > > > - In the error path of the probe function, clk_put() could be called > > > twice for the same clock. > > > > > > In order to clean this up, use the managed function devm_clk_get() and > > > store the pointer to the clk in the driver data. > > ... > > > > /* Not all platforms can gate the clock, so it is not > > > an error if the clock does not exists. */ > > > - clk = clk_get(&pdev->dev, NULL); > > > - if (!IS_ERR(clk)) { > > > - clk_prepare_enable(clk); > > > - clk_put(clk); > > > - } > > > + info->clk = devm_clk_get(&pdev->dev, NULL); > > > + if (!IS_ERR(info->clk)) > > > + clk_prepare_enable(info->clk); > > > > Orthogonal to your patch I suggest: > > > > - info->clk = devm_clk_get(&pdev->dev, NULL); > > - if (!IS_ERR(info->clk)) > > - clk_prepare_enable(info->clk); > > + info->clk = devm_clk_get_optional(&pdev->dev, NULL); > > + if (IS_ERR(info->clk)) { > > + ret = PTR_ERR(info->clk); > > + if (ret != -EPROBE_DEFER) > > + dev_err(...); > > + return ret; > > + } > > > > to correct error handling. > > (I didn't check if a plain return is right here, and also other users of > > info->clk need adaption.) > > Nice! However, I can't find a devm_clk_get_optional() anywhere(?) Is > it in some upcoming patch? Oh really. I was sure I already made use of it. Probably consfused it with the gpio or regulator API which have such variants. (But be aware, they are sematically different. If you look for a place to copy from please stick to the gpio sematic.) Then either send a patch creating clk_get_optional and friends, or only ignore -ENODEV but propagate the other error values. (Maybe the most rational path is to do both and switch the driver once clk_get_optional is available.) Best regards Uwe
Hi Simon, On Sun, 12 Mar 2017 22:34:06 +0100 Simon Baatz <gmbnomis@gmail.com> wrote: > The clk handling in orion_nand.c had two problems: > > - In the probe function, clk_put() was called for an enabled clock, > which violates the API (see documentation for clk_put() in > include/linux/clk.h) > > - In the error path of the probe function, clk_put() could be called > twice for the same clock. > > In order to clean this up, use the managed function devm_clk_get() and > store the pointer to the clk in the driver data. > > Fixes: baffab28b13120694fa3ebab08d3e99667a851d2 ('ARM: Orion: fix driver probe error handling with respect to clk') > Cc: <stable@vger.kernel.org> # v4.5+ > Signed-off-by: Simon Baatz <gmbnomis@gmail.com> > --- > drivers/mtd/nand/orion_nand.c | 42 +++++++++++++++++++++--------------------- > 1 file changed, 21 insertions(+), 21 deletions(-) > > diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c > index 4a91c5d000be..b355aa738fae 100644 > --- a/drivers/mtd/nand/orion_nand.c > +++ b/drivers/mtd/nand/orion_nand.c > @@ -23,6 +23,11 @@ > #include <asm/sizes.h> > #include <linux/platform_data/mtd-orion_nand.h> > > +struct orion_nand_info { > + struct nand_chip chip; > + struct clk *clk; Can we avoid this kind of alignment, which will not be preserved if someone adds a new field with a type that is longer than "struct nand_chip "? Regards, Boris
On Mon, 13 Mar 2017 08:12:41 +0100 Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > Hello Simon, > > On Sun, Mar 12, 2017 at 10:34:06PM +0100, Simon Baatz wrote: > > The clk handling in orion_nand.c had two problems: > > > > - In the probe function, clk_put() was called for an enabled clock, > > which violates the API (see documentation for clk_put() in > > include/linux/clk.h) > > > > - In the error path of the probe function, clk_put() could be called > > twice for the same clock. > > > > In order to clean this up, use the managed function devm_clk_get() and > > store the pointer to the clk in the driver data. > > > > Fixes: baffab28b13120694fa3ebab08d3e99667a851d2 ('ARM: Orion: fix driver probe error handling with respect to clk') > > Cc: <stable@vger.kernel.org> # v4.5+ > > Signed-off-by: Simon Baatz <gmbnomis@gmail.com> > > --- > > drivers/mtd/nand/orion_nand.c | 42 +++++++++++++++++++++--------------------- > > 1 file changed, 21 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c > > index 4a91c5d000be..b355aa738fae 100644 > > --- a/drivers/mtd/nand/orion_nand.c > > +++ b/drivers/mtd/nand/orion_nand.c > > @@ -23,6 +23,11 @@ > > #include <asm/sizes.h> > > #include <linux/platform_data/mtd-orion_nand.h> > > > > +struct orion_nand_info { > > + struct nand_chip chip; > > + struct clk *clk; > > +}; > > + > > static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) > > { > > struct nand_chip *nc = mtd_to_nand(mtd); > > @@ -75,20 +80,21 @@ static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) > > > > static int __init orion_nand_probe(struct platform_device *pdev) > > { > > + struct orion_nand_info *info; > > struct mtd_info *mtd; > > struct nand_chip *nc; > > struct orion_nand_data *board; > > struct resource *res; > > - struct clk *clk; > > void __iomem *io_base; > > int ret = 0; > > u32 val = 0; > > > > - nc = devm_kzalloc(&pdev->dev, > > - sizeof(struct nand_chip), > > + info = devm_kzalloc(&pdev->dev, > > + sizeof(struct orion_nand_info), > > GFP_KERNEL); > > - if (!nc) > > + if (!info) > > return -ENOMEM; > > + nc = &info->chip; > > mtd = nand_to_mtd(nc); > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > @@ -145,15 +151,13 @@ static int __init orion_nand_probe(struct platform_device *pdev) > > if (board->dev_ready) > > nc->dev_ready = board->dev_ready; > > > > - platform_set_drvdata(pdev, mtd); > > + platform_set_drvdata(pdev, info); > > > > /* Not all platforms can gate the clock, so it is not > > an error if the clock does not exists. */ > > - clk = clk_get(&pdev->dev, NULL); > > - if (!IS_ERR(clk)) { > > - clk_prepare_enable(clk); > > - clk_put(clk); > > - } > > + info->clk = devm_clk_get(&pdev->dev, NULL); > > + if (!IS_ERR(info->clk)) > > + clk_prepare_enable(info->clk); > > Orthogonal to your patch I suggest: > > - info->clk = devm_clk_get(&pdev->dev, NULL); > - if (!IS_ERR(info->clk)) > - clk_prepare_enable(info->clk); > + info->clk = devm_clk_get_optional(&pdev->dev, NULL); > + if (IS_ERR(info->clk)) { > + ret = PTR_ERR(info->clk); > + if (ret != -EPROBE_DEFER) > + dev_err(...); > + return ret; > + } > In the meantime, maybe you can do: info->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(info->clk)) { ret = PTR_ERR(info->clk); if (ret == -ENOENT) { /* * This clk is optional, assign it to NULL when * it's not present. */ info->clk = NULL; } else { if (ret == -EPROBE_DEFER) dev_err(...); return ret; } } This way, you won't have to check the info->clk value when you call clk_prepare_enable() or clk_disable_unprepare().
Hello Boris, On Thu, Mar 16, 2017 at 10:05:39AM +0100, Boris Brezillon wrote: > Hi Simon, > > On Sun, 12 Mar 2017 22:34:06 +0100 > Simon Baatz <gmbnomis@gmail.com> wrote: > > > The clk handling in orion_nand.c had two problems: > > > > - In the probe function, clk_put() was called for an enabled clock, > > which violates the API (see documentation for clk_put() in > > include/linux/clk.h) > > > > - In the error path of the probe function, clk_put() could be called > > twice for the same clock. > > > > In order to clean this up, use the managed function devm_clk_get() and > > store the pointer to the clk in the driver data. > > > > Fixes: baffab28b13120694fa3ebab08d3e99667a851d2 ('ARM: Orion: fix driver probe error handling with respect to clk') > > Cc: <stable@vger.kernel.org> # v4.5+ > > Signed-off-by: Simon Baatz <gmbnomis@gmail.com> > > --- > > drivers/mtd/nand/orion_nand.c | 42 +++++++++++++++++++++--------------------- > > 1 file changed, 21 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c > > index 4a91c5d000be..b355aa738fae 100644 > > --- a/drivers/mtd/nand/orion_nand.c > > +++ b/drivers/mtd/nand/orion_nand.c > > @@ -23,6 +23,11 @@ > > #include <asm/sizes.h> > > #include <linux/platform_data/mtd-orion_nand.h> > > > > +struct orion_nand_info { > > + struct nand_chip chip; > > + struct clk *clk; > > Can we avoid this kind of alignment, which will not be preserved if > someone adds a new field with a type that is longer than "struct > nand_chip "? > Sure. I will change that in v2. - Simon
On Thu, Mar 16, 2017 at 10:12:11AM +0100, Boris Brezillon wrote: > On Mon, 13 Mar 2017 08:12:41 +0100 > Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > > > Hello Simon, > > > > On Sun, Mar 12, 2017 at 10:34:06PM +0100, Simon Baatz wrote: > > > The clk handling in orion_nand.c had two problems: > > > > > > - In the probe function, clk_put() was called for an enabled clock, > > > which violates the API (see documentation for clk_put() in > > > include/linux/clk.h) > > > > > > - In the error path of the probe function, clk_put() could be called > > > twice for the same clock. > > > > > > In order to clean this up, use the managed function devm_clk_get() and > > > store the pointer to the clk in the driver data. > > > > > > Fixes: baffab28b13120694fa3ebab08d3e99667a851d2 ('ARM: Orion: fix driver probe error handling with respect to clk') > > > Cc: <stable@vger.kernel.org> # v4.5+ > > > Signed-off-by: Simon Baatz <gmbnomis@gmail.com> > > > --- > > > drivers/mtd/nand/orion_nand.c | 42 +++++++++++++++++++++--------------------- > > > 1 file changed, 21 insertions(+), 21 deletions(-) > > > > > > diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c > > > index 4a91c5d000be..b355aa738fae 100644 > > > --- a/drivers/mtd/nand/orion_nand.c > > > +++ b/drivers/mtd/nand/orion_nand.c > > > @@ -23,6 +23,11 @@ > > > #include <asm/sizes.h> > > > #include <linux/platform_data/mtd-orion_nand.h> > > > > > > +struct orion_nand_info { > > > + struct nand_chip chip; > > > + struct clk *clk; > > > +}; > > > + > > > static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) > > > { > > > struct nand_chip *nc = mtd_to_nand(mtd); > > > @@ -75,20 +80,21 @@ static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) > > > > > > static int __init orion_nand_probe(struct platform_device *pdev) > > > { > > > + struct orion_nand_info *info; > > > struct mtd_info *mtd; > > > struct nand_chip *nc; > > > struct orion_nand_data *board; > > > struct resource *res; > > > - struct clk *clk; > > > void __iomem *io_base; > > > int ret = 0; > > > u32 val = 0; > > > > > > - nc = devm_kzalloc(&pdev->dev, > > > - sizeof(struct nand_chip), > > > + info = devm_kzalloc(&pdev->dev, > > > + sizeof(struct orion_nand_info), > > > GFP_KERNEL); > > > - if (!nc) > > > + if (!info) > > > return -ENOMEM; > > > + nc = &info->chip; > > > mtd = nand_to_mtd(nc); > > > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > @@ -145,15 +151,13 @@ static int __init orion_nand_probe(struct platform_device *pdev) > > > if (board->dev_ready) > > > nc->dev_ready = board->dev_ready; > > > > > > - platform_set_drvdata(pdev, mtd); > > > + platform_set_drvdata(pdev, info); > > > > > > /* Not all platforms can gate the clock, so it is not > > > an error if the clock does not exists. */ > > > - clk = clk_get(&pdev->dev, NULL); > > > - if (!IS_ERR(clk)) { > > > - clk_prepare_enable(clk); > > > - clk_put(clk); > > > - } > > > + info->clk = devm_clk_get(&pdev->dev, NULL); > > > + if (!IS_ERR(info->clk)) > > > + clk_prepare_enable(info->clk); > > > > Orthogonal to your patch I suggest: > > > > - info->clk = devm_clk_get(&pdev->dev, NULL); > > - if (!IS_ERR(info->clk)) > > - clk_prepare_enable(info->clk); > > + info->clk = devm_clk_get_optional(&pdev->dev, NULL); > > + if (IS_ERR(info->clk)) { > > + ret = PTR_ERR(info->clk); > > + if (ret != -EPROBE_DEFER) > > + dev_err(...); > > + return ret; > > + } > > > > In the meantime, maybe you can do: > > info->clk = devm_clk_get(&pdev->dev, NULL); > if (IS_ERR(info->clk)) { > ret = PTR_ERR(info->clk); > > if (ret == -ENOENT) { > /* > * This clk is optional, assign it to NULL when > * it's not present. > */ > info->clk = NULL; > } else { > if (ret == -EPROBE_DEFER) > dev_err(...); > > return ret; > } > } > > This way, you won't have to check the info->clk value when you call > clk_prepare_enable() or clk_disable_unprepare(). > Yes, this makes things simpler. I will add a second patch improving the error handling in v2 as you and Uwe suggested. - Simon
On Thu, 16 Mar 2017 22:50:31 +0100 Simon Baatz <gmbnomis@gmail.com> wrote: > On Thu, Mar 16, 2017 at 10:12:11AM +0100, Boris Brezillon wrote: > > On Mon, 13 Mar 2017 08:12:41 +0100 > > Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > > > > > Hello Simon, > > > > > > On Sun, Mar 12, 2017 at 10:34:06PM +0100, Simon Baatz wrote: > > > > The clk handling in orion_nand.c had two problems: > > > > > > > > - In the probe function, clk_put() was called for an enabled clock, > > > > which violates the API (see documentation for clk_put() in > > > > include/linux/clk.h) > > > > > > > > - In the error path of the probe function, clk_put() could be called > > > > twice for the same clock. > > > > > > > > In order to clean this up, use the managed function devm_clk_get() and > > > > store the pointer to the clk in the driver data. > > > > > > > > Fixes: baffab28b13120694fa3ebab08d3e99667a851d2 ('ARM: Orion: fix driver probe error handling with respect to clk') > > > > Cc: <stable@vger.kernel.org> # v4.5+ > > > > Signed-off-by: Simon Baatz <gmbnomis@gmail.com> > > > > --- > > > > drivers/mtd/nand/orion_nand.c | 42 +++++++++++++++++++++--------------------- > > > > 1 file changed, 21 insertions(+), 21 deletions(-) > > > > > > > > diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c > > > > index 4a91c5d000be..b355aa738fae 100644 > > > > --- a/drivers/mtd/nand/orion_nand.c > > > > +++ b/drivers/mtd/nand/orion_nand.c > > > > @@ -23,6 +23,11 @@ > > > > #include <asm/sizes.h> > > > > #include <linux/platform_data/mtd-orion_nand.h> > > > > > > > > +struct orion_nand_info { > > > > + struct nand_chip chip; > > > > + struct clk *clk; > > > > +}; > > > > + > > > > static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) > > > > { > > > > struct nand_chip *nc = mtd_to_nand(mtd); > > > > @@ -75,20 +80,21 @@ static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) > > > > > > > > static int __init orion_nand_probe(struct platform_device *pdev) > > > > { > > > > + struct orion_nand_info *info; > > > > struct mtd_info *mtd; > > > > struct nand_chip *nc; > > > > struct orion_nand_data *board; > > > > struct resource *res; > > > > - struct clk *clk; > > > > void __iomem *io_base; > > > > int ret = 0; > > > > u32 val = 0; > > > > > > > > - nc = devm_kzalloc(&pdev->dev, > > > > - sizeof(struct nand_chip), > > > > + info = devm_kzalloc(&pdev->dev, > > > > + sizeof(struct orion_nand_info), > > > > GFP_KERNEL); > > > > - if (!nc) > > > > + if (!info) > > > > return -ENOMEM; > > > > + nc = &info->chip; > > > > mtd = nand_to_mtd(nc); > > > > > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > > @@ -145,15 +151,13 @@ static int __init orion_nand_probe(struct platform_device *pdev) > > > > if (board->dev_ready) > > > > nc->dev_ready = board->dev_ready; > > > > > > > > - platform_set_drvdata(pdev, mtd); > > > > + platform_set_drvdata(pdev, info); > > > > > > > > /* Not all platforms can gate the clock, so it is not > > > > an error if the clock does not exists. */ > > > > - clk = clk_get(&pdev->dev, NULL); > > > > - if (!IS_ERR(clk)) { > > > > - clk_prepare_enable(clk); > > > > - clk_put(clk); > > > > - } > > > > + info->clk = devm_clk_get(&pdev->dev, NULL); > > > > + if (!IS_ERR(info->clk)) > > > > + clk_prepare_enable(info->clk); > > > > > > Orthogonal to your patch I suggest: > > > > > > - info->clk = devm_clk_get(&pdev->dev, NULL); > > > - if (!IS_ERR(info->clk)) > > > - clk_prepare_enable(info->clk); > > > + info->clk = devm_clk_get_optional(&pdev->dev, NULL); > > > + if (IS_ERR(info->clk)) { > > > + ret = PTR_ERR(info->clk); > > > + if (ret != -EPROBE_DEFER) > > > + dev_err(...); > > > + return ret; > > > + } > > > > > > > In the meantime, maybe you can do: > > > > info->clk = devm_clk_get(&pdev->dev, NULL); > > if (IS_ERR(info->clk)) { > > ret = PTR_ERR(info->clk); > > > > if (ret == -ENOENT) { > > /* > > * This clk is optional, assign it to NULL when > > * it's not present. > > */ > > info->clk = NULL; > > } else { > > if (ret == -EPROBE_DEFER) I meant != -EPROBE_DEFER here. > > dev_err(...); > > > > return ret; > > } > > } > > > > This way, you won't have to check the info->clk value when you call > > clk_prepare_enable() or clk_disable_unprepare(). > > > > Yes, this makes things simpler. I will add a second patch improving > the error handling in v2 as you and Uwe suggested. > > > - Simon
diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c index 4a91c5d000be..b355aa738fae 100644 --- a/drivers/mtd/nand/orion_nand.c +++ b/drivers/mtd/nand/orion_nand.c @@ -23,6 +23,11 @@ #include <asm/sizes.h> #include <linux/platform_data/mtd-orion_nand.h> +struct orion_nand_info { + struct nand_chip chip; + struct clk *clk; +}; + static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) { struct nand_chip *nc = mtd_to_nand(mtd); @@ -75,20 +80,21 @@ static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) static int __init orion_nand_probe(struct platform_device *pdev) { + struct orion_nand_info *info; struct mtd_info *mtd; struct nand_chip *nc; struct orion_nand_data *board; struct resource *res; - struct clk *clk; void __iomem *io_base; int ret = 0; u32 val = 0; - nc = devm_kzalloc(&pdev->dev, - sizeof(struct nand_chip), + info = devm_kzalloc(&pdev->dev, + sizeof(struct orion_nand_info), GFP_KERNEL); - if (!nc) + if (!info) return -ENOMEM; + nc = &info->chip; mtd = nand_to_mtd(nc); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -145,15 +151,13 @@ static int __init orion_nand_probe(struct platform_device *pdev) if (board->dev_ready) nc->dev_ready = board->dev_ready; - platform_set_drvdata(pdev, mtd); + platform_set_drvdata(pdev, info); /* Not all platforms can gate the clock, so it is not an error if the clock does not exists. */ - clk = clk_get(&pdev->dev, NULL); - if (!IS_ERR(clk)) { - clk_prepare_enable(clk); - clk_put(clk); - } + info->clk = devm_clk_get(&pdev->dev, NULL); + if (!IS_ERR(info->clk)) + clk_prepare_enable(info->clk); ret = nand_scan(mtd, 1); if (ret) @@ -169,26 +173,22 @@ static int __init orion_nand_probe(struct platform_device *pdev) return 0; no_dev: - if (!IS_ERR(clk)) { - clk_disable_unprepare(clk); - clk_put(clk); - } + if (!IS_ERR(info->clk)) + clk_disable_unprepare(info->clk); return ret; } static int orion_nand_remove(struct platform_device *pdev) { - struct mtd_info *mtd = platform_get_drvdata(pdev); - struct clk *clk; + struct orion_nand_info *info = platform_get_drvdata(pdev); + struct nand_chip *chip = &info->chip; + struct mtd_info *mtd = nand_to_mtd(chip); nand_release(mtd); - clk = clk_get(&pdev->dev, NULL); - if (!IS_ERR(clk)) { - clk_disable_unprepare(clk); - clk_put(clk); - } + if (!IS_ERR(info->clk)) + clk_disable_unprepare(info->clk); return 0; }
The clk handling in orion_nand.c had two problems: - In the probe function, clk_put() was called for an enabled clock, which violates the API (see documentation for clk_put() in include/linux/clk.h) - In the error path of the probe function, clk_put() could be called twice for the same clock. In order to clean this up, use the managed function devm_clk_get() and store the pointer to the clk in the driver data. Fixes: baffab28b13120694fa3ebab08d3e99667a851d2 ('ARM: Orion: fix driver probe error handling with respect to clk') Cc: <stable@vger.kernel.org> # v4.5+ Signed-off-by: Simon Baatz <gmbnomis@gmail.com> --- drivers/mtd/nand/orion_nand.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-)