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From: Marcin Wojtas <mw@semihalf.com>
To: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Rob Herring <robh@kernel.org>,
	Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	netdev <netdev@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Frank Rowand <frowand.list@gmail.com>
Subject: Re: [PATCH 1/2] net: mvneta: remove bogus use of
Date: Fri, 4 Aug 2017 17:49:59 +0200	[thread overview]
Message-ID: <CAPv3WKfvAfFiDWemV67qyO1maaegi7OYW+EJrFSKn2CWqzRMRQ@mail.gmail.com> (raw)
In-Reply-To: <87tw1n73r9.fsf@free-electrons.com>

Hi Gregory,

>From my side: +1 to your modification.

Thanks,
Marcin

2017-08-04 17:26 GMT+02:00 Gregory CLEMENT <gregory.clement@free-electrons.com>:
> Hi Rob,
>
>  On jeu., juil. 20 2017, Rob Herring <robh@kernel.org> wrote:
>
>> On Thu, Jul 20, 2017 at 10:06 AM, Gregory CLEMENT
>> <gregory.clement@free-electrons.com> wrote:
>>> Hi Rob,
>>>
>>>  On jeu., juil. 20 2017, Rob Herring <robh@kernel.org> wrote:
>>>
>>> (Adding Marcin in CC who wrote this part of code)
>>>
>>>> Nothing sets ever sets data, so it is always NULL. Remove it as this is
>>>> the only user of data ptr in the whole kernel, and it is going to be
>>>> removed from struct device_node.
>>>
>>> Actually the use of device_node.data ptr is not bogus and it is set in
>>> mvneta_bm_probe:
>>> http://elixir.free-electrons.com/linux/latest/source/drivers/net/ethernet/marvell/mvneta_bm.c#L433
>>
>> Indeed. Looks like some complicated kconfig logic, so I'd not been
>> able to trigger a build failure nor did 0-day (so far).
>>
>>> Your patch will break the BM support on this driver. So if you need to
>>> remove this data ptr, then you have to offer an alternative for it.
>>
>> How about something like this (WS damaged) patch:
>
> I finally took time to test your patch. There was some missing part
> which prevented it to be build, like including linux/of_platform.h, or
> providing tub function when CONFIG_MVNETA_BM was not enable.
>
> Also the fact that you still call mvneta_bm_port_init() even if bm_priv
> was NULL was not really nice. So I proposed the following patch, that I
> tested on a clearfog with and without CONFIG_MVNETA_BM enabled.
>
> From 03c4028bc1f52d3d214e8506d9f0f66660d3985d Mon Sep 17 00:00:00 2001
> From: Gregory CLEMENT <gregory.clement@free-electrons.com>
> Date: Fri, 4 Aug 2017 17:18:38 +0200
> Subject: [PATCH] net: mvneta: remove data pointer usage from device_node
>  structure
>
> In order to be able to remove the data pointer from the device_node
> structure. We have to modify the way the BM resources are shared between
> the mvneta port.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
>  drivers/net/ethernet/marvell/mvneta.c    | 18 ++++++++++++------
>  drivers/net/ethernet/marvell/mvneta_bm.c | 13 +++++++++++++
>  drivers/net/ethernet/marvell/mvneta_bm.h |  8 ++++++--
>  3 files changed, 31 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> index 63b6147753fe..fd84447582f7 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -4295,12 +4295,16 @@ static int mvneta_probe(struct platform_device *pdev)
>
>         /* Obtain access to BM resources if enabled and already initialized */
>         bm_node = of_parse_phandle(dn, "buffer-manager", 0);
> -       if (bm_node && bm_node->data) {
> -               pp->bm_priv = bm_node->data;
> -               err = mvneta_bm_port_init(pdev, pp);
> -               if (err < 0) {
> -                       dev_info(&pdev->dev, "use SW buffer management\n");
> -                       pp->bm_priv = NULL;
> +       if (bm_node) {
> +               pp->bm_priv = mvneta_bm_get(bm_node);
> +               if (pp->bm_priv) {
> +                       err = mvneta_bm_port_init(pdev, pp);
> +                       if (err < 0) {
> +                               dev_info(&pdev->dev,
> +                                        "use SW buffer management\n");
> +                               mvneta_bm_put(pp->bm_priv);
> +                               pp->bm_priv = NULL;
> +                       }
>                 }
>         }
>         of_node_put(bm_node);
> @@ -4369,6 +4373,7 @@ static int mvneta_probe(struct platform_device *pdev)
>                 mvneta_bm_pool_destroy(pp->bm_priv, pp->pool_long, 1 << pp->id);
>                 mvneta_bm_pool_destroy(pp->bm_priv, pp->pool_short,
>                                        1 << pp->id);
> +               mvneta_bm_put(pp->bm_priv);
>         }
>  err_free_stats:
>         free_percpu(pp->stats);
> @@ -4410,6 +4415,7 @@ static int mvneta_remove(struct platform_device *pdev)
>                 mvneta_bm_pool_destroy(pp->bm_priv, pp->pool_long, 1 << pp->id);
>                 mvneta_bm_pool_destroy(pp->bm_priv, pp->pool_short,
>                                        1 << pp->id);
> +               mvneta_bm_put(pp->bm_priv);
>         }
>
>         return 0;
> diff --git a/drivers/net/ethernet/marvell/mvneta_bm.c b/drivers/net/ethernet/marvell/mvneta_bm.c
> index 466939f8f0cf..01e3152e76c8 100644
> --- a/drivers/net/ethernet/marvell/mvneta_bm.c
> +++ b/drivers/net/ethernet/marvell/mvneta_bm.c
> @@ -18,6 +18,7 @@
>  #include <linux/module.h>
>  #include <linux/netdevice.h>
>  #include <linux/of.h>
> +#include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>  #include <linux/skbuff.h>
>  #include <net/hwbm.h>
> @@ -392,6 +393,18 @@ static void mvneta_bm_put_sram(struct mvneta_bm *priv)
>                       MVNETA_BM_BPPI_SIZE);
>  }
>
> +struct mvneta_bm *mvneta_bm_get(struct device_node *node)
> +{
> +       struct platform_device *pdev = of_find_device_by_node(node);
> +
> +       return pdev ? platform_get_drvdata(pdev) : NULL;
> +}
> +
> +void mvneta_bm_put(struct mvneta_bm *priv)
> +{
> +       platform_device_put(priv->pdev);
> +}
> +
>  static int mvneta_bm_probe(struct platform_device *pdev)
>  {
>         struct device_node *dn = pdev->dev.of_node;
> diff --git a/drivers/net/ethernet/marvell/mvneta_bm.h b/drivers/net/ethernet/marvell/mvneta_bm.h
> index a32de432800c..daa9a91d2708 100644
> --- a/drivers/net/ethernet/marvell/mvneta_bm.h
> +++ b/drivers/net/ethernet/marvell/mvneta_bm.h
> @@ -134,6 +134,9 @@ void *mvneta_frag_alloc(unsigned int frag_size);
>  void mvneta_frag_free(unsigned int frag_size, void *data);
>
>  #if IS_ENABLED(CONFIG_MVNETA_BM)
> +struct mvneta_bm *mvneta_bm_get(struct device_node *node);
> +void mvneta_bm_put(struct mvneta_bm *priv);
> +
>  void mvneta_bm_pool_destroy(struct mvneta_bm *priv,
>                             struct mvneta_bm_pool *bm_pool, u8 port_map);
>  void mvneta_bm_bufs_free(struct mvneta_bm *priv, struct mvneta_bm_pool *bm_pool,
> @@ -176,7 +179,8 @@ static inline void mvneta_bm_pool_put_bp(struct mvneta_bm *priv,
>                                          dma_addr_t buf_phys_addr) {}
>
>  static inline u32 mvneta_bm_pool_get_bp(struct mvneta_bm *priv,
> -                                       struct mvneta_bm_pool *bm_pool)
> -{ return 0; }
> +                               struct mvneta_bm_pool *bm_pool) { return 0; }
> +struct mvneta_bm *mvneta_bm_get(struct device_node *node) {return NULL; }
> +void mvneta_bm_put(struct mvneta_bm *priv) {}
>  #endif /* CONFIG_MVNETA_BM */
>  #endif
> --
> 2.13.2
>
>
>
>>
>> diff --git a/drivers/net/ethernet/marvell/mvneta.c
>> b/drivers/net/ethernet/marvell/mvneta.c
>> index 0aab74c2a209..3a3021cb93a7 100644
>> --- a/drivers/net/ethernet/marvell/mvneta.c
>> +++ b/drivers/net/ethernet/marvell/mvneta.c
>> @@ -4296,11 +4296,12 @@ static int mvneta_probe(struct platform_device *pdev)
>>
>>   /* Obtain access to BM resources if enabled and already initialized */
>>   bm_node = of_parse_phandle(dn, "buffer-manager", 0);
>> - if (bm_node && bm_node->data) {
>> - pp->bm_priv = bm_node->data;
>> + if (bm_node) {
>> + pp->bm_priv = mvneta_bm_get();
>>   err = mvneta_bm_port_init(pdev, pp);
>>   if (err < 0) {
>>   dev_info(&pdev->dev, "use SW buffer management\n");
>> + mvneta_bm_put(pp->bm_priv);
>>   pp->bm_priv = NULL;
>>   }
>>   }
>> @@ -4370,6 +4371,7 @@ static int mvneta_probe(struct platform_device *pdev)
>>   mvneta_bm_pool_destroy(pp->bm_priv, pp->pool_long, 1 << pp->id);
>>   mvneta_bm_pool_destroy(pp->bm_priv, pp->pool_short,
>>         1 << pp->id);
>> + mvneta_bm_put(pp->bm_priv);
>>   }
>>  err_free_stats:
>>   free_percpu(pp->stats);
>> @@ -4411,6 +4413,7 @@ static int mvneta_remove(struct platform_device *pdev)
>>   mvneta_bm_pool_destroy(pp->bm_priv, pp->pool_long, 1 << pp->id);
>>   mvneta_bm_pool_destroy(pp->bm_priv, pp->pool_short,
>>         1 << pp->id);
>> + mvneta_bm_put(pp->bm_priv);
>>   }
>>
>>   return 0;
>> diff --git a/drivers/net/ethernet/marvell/mvneta_bm.c
>> b/drivers/net/ethernet/marvell/mvneta_bm.c
>> index 466939f8f0cf..276af8aff3c7 100644
>> --- a/drivers/net/ethernet/marvell/mvneta_bm.c
>> +++ b/drivers/net/ethernet/marvell/mvneta_bm.c
>> @@ -392,6 +392,17 @@ static void mvneta_bm_put_sram(struct mvneta_bm *priv)
>>        MVNETA_BM_BPPI_SIZE);
>>  }
>>
>> +struct mvneta_bm *mvneta_bm_get(struct device_node *node)
>> +{
>> + struct platform_device *pdev = of_find_device_by_node(node);
>> + return pdev ? platform_get_drvdata(pdev) : NULL;
>> +}
>> +
>> +void mvneta_bm_put(struct mvneta_bm *priv)
>> +{
>> + platform_device_put(priv->pdev);
>> +}
>> +
>>  static int mvneta_bm_probe(struct platform_device *pdev)
>>  {
>>   struct device_node *dn = pdev->dev.of_node;
>> diff --git a/drivers/net/ethernet/marvell/mvneta_bm.h
>> b/drivers/net/ethernet/marvell/mvneta_bm.h
>> index a32de432800c..50b27feab666 100644
>> --- a/drivers/net/ethernet/marvell/mvneta_bm.h
>> +++ b/drivers/net/ethernet/marvell/mvneta_bm.h
>> @@ -134,6 +134,9 @@ void *mvneta_frag_alloc(unsigned int frag_size);
>>  void mvneta_frag_free(unsigned int frag_size, void *data);
>>
>>  #if IS_ENABLED(CONFIG_MVNETA_BM)
>> +struct mvneta_bm *mvneta_bm_get(struct device_node *node);
>> +void mvneta_bm_put(struct mvneta_bm *priv);
>> +
>>  void mvneta_bm_pool_destroy(struct mvneta_bm *priv,
>>      struct mvneta_bm_pool *bm_pool, u8 port_map);
>>  void mvneta_bm_bufs_free(struct mvneta_bm *priv, struct
>> mvneta_bm_pool *bm_pool,
>> @@ -160,6 +163,12 @@ static inline u32 mvneta_bm_pool_get_bp(struct
>> mvneta_bm *priv,
>>       (bm_pool->id << MVNETA_BM_POOL_ACCESS_OFFS));
>>  }
>>  #else
>> +static inline struct mvneta_bm *mvneta_bm_get(struct device_node *node)
>> +{
>> + return NULL;
>> +}
>> +static inline void mvneta_bm_put(struct mvneta_bm *priv) {}
>> +
>>  void mvneta_bm_pool_destroy(struct mvneta_bm *priv,
>>      struct mvneta_bm_pool *bm_pool, u8 port_map) {}
>>  void mvneta_bm_bufs_free(struct mvneta_bm *priv, struct
>> mvneta_bm_pool *bm_pool,
>
> --
> Gregory Clement, Free Electrons
> Kernel, drivers, real-time and embedded Linux
> development, consulting, training and support.
> http://free-electrons.com

  reply	other threads:[~2017-08-04 15:49 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-20 14:27 [PATCH 1/2] net: mvneta: remove bogus use of device_node.data ptr Rob Herring
2017-07-20 14:27 ` [PATCH 2/2] of: remove unused struct " Rob Herring
2017-07-20 15:06 ` [PATCH 1/2] net: mvneta: remove bogus use of Gregory CLEMENT
2017-07-20 16:01   ` Marcin Wojtas
2017-07-20 16:02   ` Rob Herring
     [not found]     ` <CAL_JsqKTwju4=J=X1kvk=77fE1VddPh2N-wCi3A0mCAu+Qg1mA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-08-04 15:26       ` Gregory CLEMENT
2017-08-04 15:49         ` Marcin Wojtas [this message]
     [not found] ` <20170720142711.12847-1-robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2017-07-20 17:02   ` [PATCH 1/2] net: mvneta: remove bogus use of device_node.data ptr Sergei Shtylyov

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