Re: [PATCH RFC] net: dsa: remove unnecessary phy.h include

From: Florian Fainelli <f.fainelli@gmail.com>
To: Russell King - ARM Linux <linux@armlinux.org.uk>,
	Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Cc: "David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC] net: dsa: remove unnecessary phy.h include
Date: Tue, 17 Jan 2017 17:13:44 -0800	[thread overview]
Message-ID: <c9f836b1-b99e-b812-13a0-9e59b4c6cc97@gmail.com> (raw)
In-Reply-To: <20170118001403.GJ27312@n2100.armlinux.org.uk>

On 01/17/2017 04:14 PM, Russell King - ARM Linux wrote:
> Including phy.h and phy_fixed.h into net/dsa.h causes phy*.h to be an
> unnecessary dependency for quite a large amount of the kernel.  There's
> very little which actually requires definitions from phy.h in net/dsa.h
> - the include itself only wants the declaration of a couple of
> structures and IFNAMSIZ.
> 
> Add linux/if.h for IFNAMSIZ, declarations for the structures, phy.h to
> mv88e6xxx.h as it needs it for phy_interface_t, and remove both phy.h
> and phy_fixed.h from net/dsa.h.
> 
> This patch reduces from around 800 files rebuilt to around 40 - even
> with ccache, the time difference is noticable.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

> ---
> I noticed when I touched linux/phy.h that a lot of the kernel ended up
> being unexpectedly rebuilt, as linux/netdevice.h includes net/dsa.h,
> which then then includes linux/phy.h.  I've tested this change on both
> ARM and ARM64, but I'd suggest letting the 0-day builder have a bite
> at this, and then only taking it if everyone is confident that there's
> a slim chance of any problems.  Also, it may need some rework to apply
> to davem's tree.  All of the above makes this RFC only.
> 
>  drivers/net/dsa/mv88e6xxx/mv88e6xxx.h | 1 +
>  include/net/dsa.h                     | 6 ++++--
>  2 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/dsa/mv88e6xxx/mv88e6xxx.h b/drivers/net/dsa/mv88e6xxx/mv88e6xxx.h
> index a319c06d82e3..d247b0639ed4 100644
> --- a/drivers/net/dsa/mv88e6xxx/mv88e6xxx.h
> +++ b/drivers/net/dsa/mv88e6xxx/mv88e6xxx.h
> @@ -15,6 +15,7 @@
>  #include <linux/if_vlan.h>
>  #include <linux/irq.h>
>  #include <linux/gpio/consumer.h>
> +#include <linux/phy.h>
>  
>  #ifndef UINT64_MAX
>  #define UINT64_MAX		(u64)(~((u64)0))
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index b122196d5a1f..887b2f98f9ea 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -11,15 +11,17 @@
>  #ifndef __LINUX_NET_DSA_H
>  #define __LINUX_NET_DSA_H
>  
> +#include <linux/if.h>
>  #include <linux/if_ether.h>
>  #include <linux/list.h>
>  #include <linux/timer.h>
>  #include <linux/workqueue.h>
>  #include <linux/of.h>
> -#include <linux/phy.h>
> -#include <linux/phy_fixed.h>
>  #include <linux/ethtool.h>
>  
> +struct phy_device;
> +struct fixed_phy_status;
> +
>  enum dsa_tag_protocol {
>  	DSA_TAG_PROTO_NONE = 0,
>  	DSA_TAG_PROTO_DSA,
> 


-- 
Florian