firewire: mark expected switch fall-throughs
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Message ID 20190211180356.GA27613@embeddedor
State New
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Series
  • firewire: mark expected switch fall-throughs
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Commit Message

Gustavo A. R. Silva Feb. 11, 2019, 6:03 p.m. UTC
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

drivers/firewire/core-device.c: In function ‘set_broadcast_channel’:
drivers/firewire/core-device.c:969:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
    if (data & cpu_to_be32(1 << 31)) {
       ^
drivers/firewire/core-device.c:974:3: note: here
   case RCODE_ADDRESS_ERROR:
   ^~~~
drivers/firewire/core-iso.c: In function ‘manage_channel’:
drivers/firewire/core-iso.c:308:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
    if ((data[0] & bit) == (data[1] & bit))
       ^
drivers/firewire/core-iso.c:312:3: note: here
   default:
   ^~~~~~~
drivers/firewire/core-topology.c: In function ‘count_ports’:
drivers/firewire/core-topology.c:69:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
    (*child_port_count)++;
    ~~~~~~~~~~~~~~~~~~~^~
drivers/firewire/core-topology.c:70:3: note: here
   case SELFID_PORT_PARENT:
   ^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

Notice that in some cases, the code comment is modified in
accordance with what GCC is expecting to find.

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/firewire/core-device.c   | 2 +-
 drivers/firewire/core-iso.c      | 2 +-
 drivers/firewire/core-topology.c | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

Comments

Stefan Richter March 14, 2019, 10 a.m. UTC | #1
(added Cc: Mathieu Malaterre, who sent a patch which is a subset of this)

On Feb 11 Gustavo A. R. Silva wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch
> cases where we are expecting to fall through.
> 
> This patch fixes the following warnings:
> 
> drivers/firewire/core-device.c: In function ‘set_broadcast_channel’:
> drivers/firewire/core-device.c:969:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
>     if (data & cpu_to_be32(1 << 31)) {
>        ^
> drivers/firewire/core-device.c:974:3: note: here
>    case RCODE_ADDRESS_ERROR:
>    ^~~~
> drivers/firewire/core-iso.c: In function ‘manage_channel’:
> drivers/firewire/core-iso.c:308:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
>     if ((data[0] & bit) == (data[1] & bit))
>        ^
> drivers/firewire/core-iso.c:312:3: note: here
>    default:
>    ^~~~~~~
> drivers/firewire/core-topology.c: In function ‘count_ports’:
> drivers/firewire/core-topology.c:69:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
>     (*child_port_count)++;
>     ~~~~~~~~~~~~~~~~~~~^~
> drivers/firewire/core-topology.c:70:3: note: here
>    case SELFID_PORT_PARENT:
>    ^~~~
> 
> Warning level 3 was used: -Wimplicit-fallthrough=3
> 
> Notice that in some cases, the code comment is modified in
> accordance with what GCC is expecting to find.

OK, I looked up
https://gcc.gnu.org/onlinedocs/gcc-8.3.0/gcc/Warning-Options.html#index-Wimplicit-fallthrough
now.  I am loudly sighing and rolling my eyes...  Anyway; the last regex
listed at the Wimplicit-fallthrough=3 bullet point is obviously the one
you are wanting to match.

> This patch is part of the ongoing efforts to enable
> -Wimplicit-fallthrough.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  drivers/firewire/core-device.c   | 2 +-
>  drivers/firewire/core-iso.c      | 2 +-
>  drivers/firewire/core-topology.c | 1 +
>  3 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
> index 7c2eed76011e..0c86548fa4a7 100644
> --- a/drivers/firewire/core-device.c
> +++ b/drivers/firewire/core-device.c
> @@ -970,7 +970,7 @@ static void set_broadcast_channel(struct fw_device *device, int generation)
>  				device->bc_implemented = BC_IMPLEMENTED;
>  				break;
>  			}
> -			/* else fall through to case address error */
> +			/* else, fall through - to case address error */
>  		case RCODE_ADDRESS_ERROR:
>  			device->bc_implemented = BC_UNIMPLEMENTED;
>  		}
> diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
> index 35e784cffc23..7e5c98840b80 100644
> --- a/drivers/firewire/core-iso.c
> +++ b/drivers/firewire/core-iso.c
> @@ -308,7 +308,7 @@ static int manage_channel(struct fw_card *card, int irm_id, int generation,
>  			if ((data[0] & bit) == (data[1] & bit))
>  				continue;
>  
> -			/* 1394-1995 IRM, fall through to retry. */
> +			/* fall through - to retry for 1394-1995 IRM */

If you don't mind, I will apply your patch with a different wording of this
comment:

			/* fall through - It's an 1394-1995 IRM, retry. */

I'll mark my modification to your patch in the signed-off-by-tag.

>  		default:
>  			if (retry) {
>  				retry--;
> diff --git a/drivers/firewire/core-topology.c b/drivers/firewire/core-topology.c
> index 7db234d3fbdd..82c67e900aad 100644
> --- a/drivers/firewire/core-topology.c
> +++ b/drivers/firewire/core-topology.c
> @@ -67,6 +67,7 @@ static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
>  		switch (port_type) {
>  		case SELFID_PORT_CHILD:
>  			(*child_port_count)++;
> +			/* fall through */
>  		case SELFID_PORT_PARENT:
>  		case SELFID_PORT_NCONN:
>  			(*total_port_count)++;
Gustavo A. R. Silva March 14, 2019, 6:42 p.m. UTC | #2
On 3/14/19 5:00 AM, Stefan Richter wrote:

[..]

>> diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
>> index 35e784cffc23..7e5c98840b80 100644
>> --- a/drivers/firewire/core-iso.c
>> +++ b/drivers/firewire/core-iso.c
>> @@ -308,7 +308,7 @@ static int manage_channel(struct fw_card *card, int irm_id, int generation,
>>  			if ((data[0] & bit) == (data[1] & bit))
>>  				continue;
>>  
>> -			/* 1394-1995 IRM, fall through to retry. */
>> +			/* fall through - to retry for 1394-1995 IRM */
> 
> If you don't mind, I will apply your patch with a different wording of this
> comment:
> 
> 			/* fall through - It's an 1394-1995 IRM, retry. */
> 
> I'll mark my modification to your patch in the signed-off-by-tag.
> 

Sure. That's fine with me.

Thank you.
--
Gustavo

Patch
diff mbox series

diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index 7c2eed76011e..0c86548fa4a7 100644
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -970,7 +970,7 @@  static void set_broadcast_channel(struct fw_device *device, int generation)
 				device->bc_implemented = BC_IMPLEMENTED;
 				break;
 			}
-			/* else fall through to case address error */
+			/* else, fall through - to case address error */
 		case RCODE_ADDRESS_ERROR:
 			device->bc_implemented = BC_UNIMPLEMENTED;
 		}
diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
index 35e784cffc23..7e5c98840b80 100644
--- a/drivers/firewire/core-iso.c
+++ b/drivers/firewire/core-iso.c
@@ -308,7 +308,7 @@  static int manage_channel(struct fw_card *card, int irm_id, int generation,
 			if ((data[0] & bit) == (data[1] & bit))
 				continue;
 
-			/* 1394-1995 IRM, fall through to retry. */
+			/* fall through - to retry for 1394-1995 IRM */
 		default:
 			if (retry) {
 				retry--;
diff --git a/drivers/firewire/core-topology.c b/drivers/firewire/core-topology.c
index 7db234d3fbdd..82c67e900aad 100644
--- a/drivers/firewire/core-topology.c
+++ b/drivers/firewire/core-topology.c
@@ -67,6 +67,7 @@  static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
 		switch (port_type) {
 		case SELFID_PORT_CHILD:
 			(*child_port_count)++;
+			/* fall through */
 		case SELFID_PORT_PARENT:
 		case SELFID_PORT_NCONN:
 			(*total_port_count)++;