[PATCH] kernel/drivers: Remove redundant driver match function

[PATCH] kernel/drivers: Remove redundant driver match function

[lizhe]

If there is no driver match function, the driver core assumes that each
candidate pair (driver, device) matches, see driver_match_device().

Signed-off-by: lizhe <sensor1010@163.com>
---
 drivers/mfd/mcp-core.c             |  6 ------
 drivers/nubus/bus.c                |  6 ------
 drivers/s390/crypto/vfio_ap_drv.c  |  6 ------
 drivers/scsi/scsi_debug.c          |  7 -------
 drivers/target/loopback/tcm_loop.c |  7 -------
 drivers/w1/w1.c                    |  6 ------
 sound/ac97_bus.c                   | 11 -----------
 7 files changed, 49 deletions(-)

diff --git a/drivers/mfd/mcp-core.c b/drivers/mfd/mcp-core.c
index 2fa592c37c6f..281a9369f2b3 100644
--- a/drivers/mfd/mcp-core.c
+++ b/drivers/mfd/mcp-core.c
@@ -20,11 +20,6 @@
 #define to_mcp(d)		container_of(d, struct mcp, attached_device)
 #define to_mcp_driver(d)	container_of(d, struct mcp_driver, drv)
 
-static int mcp_bus_match(struct device *dev, struct device_driver *drv)
-{
-	return 1;
-}
-
 static int mcp_bus_probe(struct device *dev)
 {
 	struct mcp *mcp = to_mcp(dev);
@@ -43,7 +38,6 @@ static void mcp_bus_remove(struct device *dev)
 
 static struct bus_type mcp_bus_type = {
 	.name		= "mcp",
-	.match		= mcp_bus_match,
 	.probe		= mcp_bus_probe,
 	.remove		= mcp_bus_remove,
 };
diff --git a/drivers/nubus/bus.c b/drivers/nubus/bus.c
index 17fad660032c..72921e4f35f6 100644
--- a/drivers/nubus/bus.c
+++ b/drivers/nubus/bus.c
@@ -14,11 +14,6 @@
 #define to_nubus_board(d)       container_of(d, struct nubus_board, dev)
 #define to_nubus_driver(d)      container_of(d, struct nubus_driver, driver)
 
-static int nubus_bus_match(struct device *dev, struct device_driver *driver)
-{
-	return 1;
-}
-
 static int nubus_device_probe(struct device *dev)
 {
 	struct nubus_driver *ndrv = to_nubus_driver(dev->driver);
@@ -39,7 +34,6 @@ static void nubus_device_remove(struct device *dev)
 
 struct bus_type nubus_bus_type = {
 	.name		= "nubus",
-	.match		= nubus_bus_match,
 	.probe		= nubus_device_probe,
 	.remove		= nubus_device_remove,
 };
diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
index 29ebd54f8919..0a662c451f2a 100644
--- a/drivers/s390/crypto/vfio_ap_drv.c
+++ b/drivers/s390/crypto/vfio_ap_drv.c
@@ -172,14 +172,8 @@ static void vfio_ap_matrix_dev_release(struct device *dev)
 	kfree(matrix_dev);
 }
 
-static int matrix_bus_match(struct device *dev, struct device_driver *drv)
-{
-	return 1;
-}
-
 static struct bus_type matrix_bus = {
 	.name = "matrix",
-	.match = &matrix_bus_match,
 };
 
 static struct device_driver matrix_driver = {
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 592a290e6cfa..8107489b36e8 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -7844,15 +7844,8 @@ static void sdebug_driver_remove(struct device *dev)
 	scsi_host_put(sdbg_host->shost);
 }
 
-static int pseudo_lld_bus_match(struct device *dev,
-				struct device_driver *dev_driver)
-{
-	return 1;
-}
-
 static struct bus_type pseudo_lld_bus = {
 	.name = "pseudo",
-	.match = pseudo_lld_bus_match,
 	.probe = sdebug_driver_probe,
 	.remove = sdebug_driver_remove,
 	.drv_groups = sdebug_drv_groups,
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 4407b56aa6d1..eeb63deff94f 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -83,15 +83,8 @@ static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
 static int tcm_loop_driver_probe(struct device *);
 static void tcm_loop_driver_remove(struct device *);
 
-static int pseudo_lld_bus_match(struct device *dev,
-				struct device_driver *dev_driver)
-{
-	return 1;
-}
-
 static struct bus_type tcm_loop_lld_bus = {
 	.name			= "tcm_loop_bus",
-	.match			= pseudo_lld_bus_match,
 	.probe			= tcm_loop_driver_probe,
 	.remove			= tcm_loop_driver_remove,
 };
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index f2ae2e563dc5..a6ecfa1b3417 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -58,11 +58,6 @@ MODULE_PARM_DESC(slave_ttl,
 DEFINE_MUTEX(w1_mlock);
 LIST_HEAD(w1_masters);
 
-static int w1_master_match(struct device *dev, struct device_driver *drv)
-{
-	return 1;
-}
-
 static int w1_master_probe(struct device *dev)
 {
 	return -ENODEV;
@@ -174,7 +169,6 @@ static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
 
 static struct bus_type w1_bus_type = {
 	.name = "w1",
-	.match = w1_master_match,
 	.uevent = w1_uevent,
 };
 
diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c
index b4685c53ff11..c7aee8c42c55 100644
--- a/sound/ac97_bus.c
+++ b/sound/ac97_bus.c
@@ -75,19 +75,8 @@ int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id,
 }
 EXPORT_SYMBOL_GPL(snd_ac97_reset);
 
-/*
- * Let drivers decide whether they want to support given codec from their
- * probe method. Drivers have direct access to the struct snd_ac97
- * structure and may  decide based on the id field amongst other things.
- */
-static int ac97_bus_match(struct device *dev, struct device_driver *drv)
-{
-	return 1;
-}
-
 struct bus_type ac97_bus_type = {
 	.name		= "ac97",
-	.match		= ac97_bus_match,
 };
 
 static int __init ac97_bus_init(void)
-- 
2.25.1

Re: [PATCH] kernel/drivers: Remove redundant driver match function

[Uwe Kleine-König]

[-- Attachment #1: Type: text/plain, Size: 691 bytes --]

Hello,

On Thu, May 05, 2022 at 09:59:52PM -0700, lizhe wrote:
> If there is no driver match function, the driver core assumes that each
> candidate pair (driver, device) matches, see driver_match_device().
> 
> Signed-off-by: lizhe <sensor1010@163.com>

Reviewed-by: Uwe Kleine-König <u.kleine-koenig.org>

Side note: While looking through this patch I was surprised to see there
are two different busses for ac97: sound/ac97/bus.c + sound/ac97_bus.c .
It seems the duplication exists since 2017.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH] kernel/drivers: Remove redundant driver match function

[Finn Thain]

On Thu, 5 May 2022, lizhe wrote:

> If there is no driver match function, the driver core assumes that each
> candidate pair (driver, device) matches, see driver_match_device().
> 
> Signed-off-by: lizhe <sensor1010@163.com>

Acked-by: Finn Thain <fthain@linux-m68k.org>
for the nubus changes.

> ---
>  drivers/mfd/mcp-core.c             |  6 ------
>  drivers/nubus/bus.c                |  6 ------
>  drivers/s390/crypto/vfio_ap_drv.c  |  6 ------
>  drivers/scsi/scsi_debug.c          |  7 -------
>  drivers/target/loopback/tcm_loop.c |  7 -------
>  drivers/w1/w1.c                    |  6 ------
>  sound/ac97_bus.c                   | 11 -----------
>  7 files changed, 49 deletions(-)
> 
> diff --git a/drivers/mfd/mcp-core.c b/drivers/mfd/mcp-core.c
> index 2fa592c37c6f..281a9369f2b3 100644
> --- a/drivers/mfd/mcp-core.c
> +++ b/drivers/mfd/mcp-core.c
> @@ -20,11 +20,6 @@
>  #define to_mcp(d)		container_of(d, struct mcp, attached_device)
>  #define to_mcp_driver(d)	container_of(d, struct mcp_driver, drv)
>  
> -static int mcp_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>  static int mcp_bus_probe(struct device *dev)
>  {
>  	struct mcp *mcp = to_mcp(dev);
> @@ -43,7 +38,6 @@ static void mcp_bus_remove(struct device *dev)
>  
>  static struct bus_type mcp_bus_type = {
>  	.name		= "mcp",
> -	.match		= mcp_bus_match,
>  	.probe		= mcp_bus_probe,
>  	.remove		= mcp_bus_remove,
>  };
> diff --git a/drivers/nubus/bus.c b/drivers/nubus/bus.c
> index 17fad660032c..72921e4f35f6 100644
> --- a/drivers/nubus/bus.c
> +++ b/drivers/nubus/bus.c
> @@ -14,11 +14,6 @@
>  #define to_nubus_board(d)       container_of(d, struct nubus_board, dev)
>  #define to_nubus_driver(d)      container_of(d, struct nubus_driver, driver)
>  
> -static int nubus_bus_match(struct device *dev, struct device_driver *driver)
> -{
> -	return 1;
> -}
> -
>  static int nubus_device_probe(struct device *dev)
>  {
>  	struct nubus_driver *ndrv = to_nubus_driver(dev->driver);
> @@ -39,7 +34,6 @@ static void nubus_device_remove(struct device *dev)
>  
>  struct bus_type nubus_bus_type = {
>  	.name		= "nubus",
> -	.match		= nubus_bus_match,
>  	.probe		= nubus_device_probe,
>  	.remove		= nubus_device_remove,
>  };
> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
> index 29ebd54f8919..0a662c451f2a 100644
> --- a/drivers/s390/crypto/vfio_ap_drv.c
> +++ b/drivers/s390/crypto/vfio_ap_drv.c
> @@ -172,14 +172,8 @@ static void vfio_ap_matrix_dev_release(struct device *dev)
>  	kfree(matrix_dev);
>  }
>  
> -static int matrix_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>  static struct bus_type matrix_bus = {
>  	.name = "matrix",
> -	.match = &matrix_bus_match,
>  };
>  
>  static struct device_driver matrix_driver = {
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index 592a290e6cfa..8107489b36e8 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -7844,15 +7844,8 @@ static void sdebug_driver_remove(struct device *dev)
>  	scsi_host_put(sdbg_host->shost);
>  }
>  
> -static int pseudo_lld_bus_match(struct device *dev,
> -				struct device_driver *dev_driver)
> -{
> -	return 1;
> -}
> -
>  static struct bus_type pseudo_lld_bus = {
>  	.name = "pseudo",
> -	.match = pseudo_lld_bus_match,
>  	.probe = sdebug_driver_probe,
>  	.remove = sdebug_driver_remove,
>  	.drv_groups = sdebug_drv_groups,
> diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
> index 4407b56aa6d1..eeb63deff94f 100644
> --- a/drivers/target/loopback/tcm_loop.c
> +++ b/drivers/target/loopback/tcm_loop.c
> @@ -83,15 +83,8 @@ static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
>  static int tcm_loop_driver_probe(struct device *);
>  static void tcm_loop_driver_remove(struct device *);
>  
> -static int pseudo_lld_bus_match(struct device *dev,
> -				struct device_driver *dev_driver)
> -{
> -	return 1;
> -}
> -
>  static struct bus_type tcm_loop_lld_bus = {
>  	.name			= "tcm_loop_bus",
> -	.match			= pseudo_lld_bus_match,
>  	.probe			= tcm_loop_driver_probe,
>  	.remove			= tcm_loop_driver_remove,
>  };
> diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
> index f2ae2e563dc5..a6ecfa1b3417 100644
> --- a/drivers/w1/w1.c
> +++ b/drivers/w1/w1.c
> @@ -58,11 +58,6 @@ MODULE_PARM_DESC(slave_ttl,
>  DEFINE_MUTEX(w1_mlock);
>  LIST_HEAD(w1_masters);
>  
> -static int w1_master_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>  static int w1_master_probe(struct device *dev)
>  {
>  	return -ENODEV;
> @@ -174,7 +169,6 @@ static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
>  
>  static struct bus_type w1_bus_type = {
>  	.name = "w1",
> -	.match = w1_master_match,
>  	.uevent = w1_uevent,
>  };
>  
> diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c
> index b4685c53ff11..c7aee8c42c55 100644
> --- a/sound/ac97_bus.c
> +++ b/sound/ac97_bus.c
> @@ -75,19 +75,8 @@ int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id,
>  }
>  EXPORT_SYMBOL_GPL(snd_ac97_reset);
>  
> -/*
> - * Let drivers decide whether they want to support given codec from their
> - * probe method. Drivers have direct access to the struct snd_ac97
> - * structure and may  decide based on the id field amongst other things.
> - */
> -static int ac97_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>  struct bus_type ac97_bus_type = {
>  	.name		= "ac97",
> -	.match		= ac97_bus_match,
>  };
>  
>  static int __init ac97_bus_init(void)
> 

Re: [PATCH] kernel/drivers: Remove redundant driver match function

[Uwe Kleine-König]

[-- Attachment #1: Type: text/plain, Size: 6163 bytes --]

Hello,

On Thu, May 05, 2022 at 09:59:52PM -0700, lizhe wrote:
> If there is no driver match function, the driver core assumes that each
> candidate pair (driver, device) matches, see driver_match_device().

I wonder who is supposed to apply this patch. Either it should be split
by file and go in via the respective maintainers, or it goes in via
Greg's tree? I added Greg to To: for him to chime in.

Best regards
Uwe
 
> Signed-off-by: lizhe <sensor1010@163.com>
> ---
>  drivers/mfd/mcp-core.c             |  6 ------
>  drivers/nubus/bus.c                |  6 ------
>  drivers/s390/crypto/vfio_ap_drv.c  |  6 ------
>  drivers/scsi/scsi_debug.c          |  7 -------
>  drivers/target/loopback/tcm_loop.c |  7 -------
>  drivers/w1/w1.c                    |  6 ------
>  sound/ac97_bus.c                   | 11 -----------
>  7 files changed, 49 deletions(-)
> 
> diff --git a/drivers/mfd/mcp-core.c b/drivers/mfd/mcp-core.c
> index 2fa592c37c6f..281a9369f2b3 100644
> --- a/drivers/mfd/mcp-core.c
> +++ b/drivers/mfd/mcp-core.c
> @@ -20,11 +20,6 @@
>  #define to_mcp(d)		container_of(d, struct mcp, attached_device)
>  #define to_mcp_driver(d)	container_of(d, struct mcp_driver, drv)
>  
> -static int mcp_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>  static int mcp_bus_probe(struct device *dev)
>  {
>  	struct mcp *mcp = to_mcp(dev);
> @@ -43,7 +38,6 @@ static void mcp_bus_remove(struct device *dev)
>  
>  static struct bus_type mcp_bus_type = {
>  	.name		= "mcp",
> -	.match		= mcp_bus_match,
>  	.probe		= mcp_bus_probe,
>  	.remove		= mcp_bus_remove,
>  };
> diff --git a/drivers/nubus/bus.c b/drivers/nubus/bus.c
> index 17fad660032c..72921e4f35f6 100644
> --- a/drivers/nubus/bus.c
> +++ b/drivers/nubus/bus.c
> @@ -14,11 +14,6 @@
>  #define to_nubus_board(d)       container_of(d, struct nubus_board, dev)
>  #define to_nubus_driver(d)      container_of(d, struct nubus_driver, driver)
>  
> -static int nubus_bus_match(struct device *dev, struct device_driver *driver)
> -{
> -	return 1;
> -}
> -
>  static int nubus_device_probe(struct device *dev)
>  {
>  	struct nubus_driver *ndrv = to_nubus_driver(dev->driver);
> @@ -39,7 +34,6 @@ static void nubus_device_remove(struct device *dev)
>  
>  struct bus_type nubus_bus_type = {
>  	.name		= "nubus",
> -	.match		= nubus_bus_match,
>  	.probe		= nubus_device_probe,
>  	.remove		= nubus_device_remove,
>  };
> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
> index 29ebd54f8919..0a662c451f2a 100644
> --- a/drivers/s390/crypto/vfio_ap_drv.c
> +++ b/drivers/s390/crypto/vfio_ap_drv.c
> @@ -172,14 +172,8 @@ static void vfio_ap_matrix_dev_release(struct device *dev)
>  	kfree(matrix_dev);
>  }
>  
> -static int matrix_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>  static struct bus_type matrix_bus = {
>  	.name = "matrix",
> -	.match = &matrix_bus_match,
>  };
>  
>  static struct device_driver matrix_driver = {
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index 592a290e6cfa..8107489b36e8 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -7844,15 +7844,8 @@ static void sdebug_driver_remove(struct device *dev)
>  	scsi_host_put(sdbg_host->shost);
>  }
>  
> -static int pseudo_lld_bus_match(struct device *dev,
> -				struct device_driver *dev_driver)
> -{
> -	return 1;
> -}
> -
>  static struct bus_type pseudo_lld_bus = {
>  	.name = "pseudo",
> -	.match = pseudo_lld_bus_match,
>  	.probe = sdebug_driver_probe,
>  	.remove = sdebug_driver_remove,
>  	.drv_groups = sdebug_drv_groups,
> diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
> index 4407b56aa6d1..eeb63deff94f 100644
> --- a/drivers/target/loopback/tcm_loop.c
> +++ b/drivers/target/loopback/tcm_loop.c
> @@ -83,15 +83,8 @@ static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
>  static int tcm_loop_driver_probe(struct device *);
>  static void tcm_loop_driver_remove(struct device *);
>  
> -static int pseudo_lld_bus_match(struct device *dev,
> -				struct device_driver *dev_driver)
> -{
> -	return 1;
> -}
> -
>  static struct bus_type tcm_loop_lld_bus = {
>  	.name			= "tcm_loop_bus",
> -	.match			= pseudo_lld_bus_match,
>  	.probe			= tcm_loop_driver_probe,
>  	.remove			= tcm_loop_driver_remove,
>  };
> diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
> index f2ae2e563dc5..a6ecfa1b3417 100644
> --- a/drivers/w1/w1.c
> +++ b/drivers/w1/w1.c
> @@ -58,11 +58,6 @@ MODULE_PARM_DESC(slave_ttl,
>  DEFINE_MUTEX(w1_mlock);
>  LIST_HEAD(w1_masters);
>  
> -static int w1_master_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>  static int w1_master_probe(struct device *dev)
>  {
>  	return -ENODEV;
> @@ -174,7 +169,6 @@ static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
>  
>  static struct bus_type w1_bus_type = {
>  	.name = "w1",
> -	.match = w1_master_match,
>  	.uevent = w1_uevent,
>  };
>  
> diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c
> index b4685c53ff11..c7aee8c42c55 100644
> --- a/sound/ac97_bus.c
> +++ b/sound/ac97_bus.c
> @@ -75,19 +75,8 @@ int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id,
>  }
>  EXPORT_SYMBOL_GPL(snd_ac97_reset);
>  
> -/*
> - * Let drivers decide whether they want to support given codec from their
> - * probe method. Drivers have direct access to the struct snd_ac97
> - * structure and may  decide based on the id field amongst other things.
> - */
> -static int ac97_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>  struct bus_type ac97_bus_type = {
>  	.name		= "ac97",
> -	.match		= ac97_bus_match,
>  };
>  
>  static int __init ac97_bus_init(void)
> -- 
> 2.25.1
> 
> 

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH] kernel/drivers: Remove redundant driver match function

[Greg Kroah-Hartman]

On Sat, May 07, 2022 at 10:21:37AM +0200, Uwe Kleine-König wrote:
> Hello,
> 
> On Thu, May 05, 2022 at 09:59:52PM -0700, lizhe wrote:
> > If there is no driver match function, the driver core assumes that each
> > candidate pair (driver, device) matches, see driver_match_device().
> 
> I wonder who is supposed to apply this patch. Either it should be split
> by file and go in via the respective maintainers, or it goes in via
> Greg's tree? I added Greg to To: for him to chime in.

It should be split up into each subsystem patch and submitted that way.

> Best regards
> Uwe
>  
> > Signed-off-by: lizhe <sensor1010@163.com>

We also need a "real name" here that is used to sign legal documents.  I
doubt an all-lower-case name is used that way, so I have to ask.

thanks,

greg k-h

Re: [PATCH] kernel/drivers: Remove redundant driver match function

[Takashi Iwai]

On Fri, 06 May 2022 08:49:27 +0200,
Uwe Kleine-König wrote:
> 
> Hello,
> 
> On Thu, May 05, 2022 at 09:59:52PM -0700, lizhe wrote:
> > If there is no driver match function, the driver core assumes that each
> > candidate pair (driver, device) matches, see driver_match_device().
> > 
> > Signed-off-by: lizhe <sensor1010@163.com>
> 
> Reviewed-by: Uwe Kleine-König <u.kleine-koenig.org>
> 
> Side note: While looking through this patch I was surprised to see there
> are two different busses for ac97: sound/ac97/bus.c + sound/ac97_bus.c .
> It seems the duplication exists since 2017.

Those are intentional and will be likely kept as-is.  In theory those
could be unified, but there are quite lots of quirk codes for the old
bus implementations and it'll be way too much work to rewrite for the
new bus.


Takashi

Re: [PATCH] kernel/drivers: Remove redundant driver match function

[Tony Krowiak]

For the drivers/s390/crypto/vfio_ap_drv.c device driver:
Reviewed-by: Tony Krowiak <akrowiak@stny.rr.com>

On 5/6/22 12:59 AM, lizhe wrote:
> If there is no driver match function, the driver core assumes that each
> candidate pair (driver, device) matches, see driver_match_device().
>
> Signed-off-by: lizhe <sensor1010@163.com>
> ---
>   drivers/mfd/mcp-core.c             |  6 ------
>   drivers/nubus/bus.c                |  6 ------
>   drivers/s390/crypto/vfio_ap_drv.c  |  6 ------
>   drivers/scsi/scsi_debug.c          |  7 -------
>   drivers/target/loopback/tcm_loop.c |  7 -------
>   drivers/w1/w1.c                    |  6 ------
>   sound/ac97_bus.c                   | 11 -----------
>   7 files changed, 49 deletions(-)
>
> diff --git a/drivers/mfd/mcp-core.c b/drivers/mfd/mcp-core.c
> index 2fa592c37c6f..281a9369f2b3 100644
> --- a/drivers/mfd/mcp-core.c
> +++ b/drivers/mfd/mcp-core.c
> @@ -20,11 +20,6 @@
>   #define to_mcp(d)		container_of(d, struct mcp, attached_device)
>   #define to_mcp_driver(d)	container_of(d, struct mcp_driver, drv)
>   
> -static int mcp_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>   static int mcp_bus_probe(struct device *dev)
>   {
>   	struct mcp *mcp = to_mcp(dev);
> @@ -43,7 +38,6 @@ static void mcp_bus_remove(struct device *dev)
>   
>   static struct bus_type mcp_bus_type = {
>   	.name		= "mcp",
> -	.match		= mcp_bus_match,
>   	.probe		= mcp_bus_probe,
>   	.remove		= mcp_bus_remove,
>   };
> diff --git a/drivers/nubus/bus.c b/drivers/nubus/bus.c
> index 17fad660032c..72921e4f35f6 100644
> --- a/drivers/nubus/bus.c
> +++ b/drivers/nubus/bus.c
> @@ -14,11 +14,6 @@
>   #define to_nubus_board(d)       container_of(d, struct nubus_board, dev)
>   #define to_nubus_driver(d)      container_of(d, struct nubus_driver, driver)
>   
> -static int nubus_bus_match(struct device *dev, struct device_driver *driver)
> -{
> -	return 1;
> -}
> -
>   static int nubus_device_probe(struct device *dev)
>   {
>   	struct nubus_driver *ndrv = to_nubus_driver(dev->driver);
> @@ -39,7 +34,6 @@ static void nubus_device_remove(struct device *dev)
>   
>   struct bus_type nubus_bus_type = {
>   	.name		= "nubus",
> -	.match		= nubus_bus_match,
>   	.probe		= nubus_device_probe,
>   	.remove		= nubus_device_remove,
>   };
> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
> index 29ebd54f8919..0a662c451f2a 100644
> --- a/drivers/s390/crypto/vfio_ap_drv.c
> +++ b/drivers/s390/crypto/vfio_ap_drv.c
> @@ -172,14 +172,8 @@ static void vfio_ap_matrix_dev_release(struct device *dev)
>   	kfree(matrix_dev);
>   }
>   
> -static int matrix_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>   static struct bus_type matrix_bus = {
>   	.name = "matrix",
> -	.match = &matrix_bus_match,
>   };
>   
>   static struct device_driver matrix_driver = {
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index 592a290e6cfa..8107489b36e8 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -7844,15 +7844,8 @@ static void sdebug_driver_remove(struct device *dev)
>   	scsi_host_put(sdbg_host->shost);
>   }
>   
> -static int pseudo_lld_bus_match(struct device *dev,
> -				struct device_driver *dev_driver)
> -{
> -	return 1;
> -}
> -
>   static struct bus_type pseudo_lld_bus = {
>   	.name = "pseudo",
> -	.match = pseudo_lld_bus_match,
>   	.probe = sdebug_driver_probe,
>   	.remove = sdebug_driver_remove,
>   	.drv_groups = sdebug_drv_groups,
> diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
> index 4407b56aa6d1..eeb63deff94f 100644
> --- a/drivers/target/loopback/tcm_loop.c
> +++ b/drivers/target/loopback/tcm_loop.c
> @@ -83,15 +83,8 @@ static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
>   static int tcm_loop_driver_probe(struct device *);
>   static void tcm_loop_driver_remove(struct device *);
>   
> -static int pseudo_lld_bus_match(struct device *dev,
> -				struct device_driver *dev_driver)
> -{
> -	return 1;
> -}
> -
>   static struct bus_type tcm_loop_lld_bus = {
>   	.name			= "tcm_loop_bus",
> -	.match			= pseudo_lld_bus_match,
>   	.probe			= tcm_loop_driver_probe,
>   	.remove			= tcm_loop_driver_remove,
>   };
> diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
> index f2ae2e563dc5..a6ecfa1b3417 100644
> --- a/drivers/w1/w1.c
> +++ b/drivers/w1/w1.c
> @@ -58,11 +58,6 @@ MODULE_PARM_DESC(slave_ttl,
>   DEFINE_MUTEX(w1_mlock);
>   LIST_HEAD(w1_masters);
>   
> -static int w1_master_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>   static int w1_master_probe(struct device *dev)
>   {
>   	return -ENODEV;
> @@ -174,7 +169,6 @@ static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
>   
>   static struct bus_type w1_bus_type = {
>   	.name = "w1",
> -	.match = w1_master_match,
>   	.uevent = w1_uevent,
>   };
>   
> diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c
> index b4685c53ff11..c7aee8c42c55 100644
> --- a/sound/ac97_bus.c
> +++ b/sound/ac97_bus.c
> @@ -75,19 +75,8 @@ int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id,
>   }
>   EXPORT_SYMBOL_GPL(snd_ac97_reset);
>   
> -/*
> - * Let drivers decide whether they want to support given codec from their
> - * probe method. Drivers have direct access to the struct snd_ac97
> - * structure and may  decide based on the id field amongst other things.
> - */
> -static int ac97_bus_match(struct device *dev, struct device_driver *drv)
> -{
> -	return 1;
> -}
> -
>   struct bus_type ac97_bus_type = {
>   	.name		= "ac97",
> -	.match		= ac97_bus_match,
>   };
>   
>   static int __init ac97_bus_init(void)