[PATCH V2] staging: fieldbus: anybus-s: consolidate wait_for_completion_timeout return handling

[PATCH V2] staging: fieldbus: anybus-s: consolidate wait_for_completion_timeout return handling

[Nicholas Mc Guire]

wait_for_completion_timeout() returns unsigned long (0 on timeout or
remaining jiffies) not int - so rather than introducing an additional
variable simply wrap the completion into an if().

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
---

Problem located with experimental API conformance checking cocci script

V2: The original patch's logic was wrong as it was skipping the 
    fall-through if so using the fix proposed by Sven Van Asbroeck 
    <thesven73@gmail.com> - This solution also eliminates the need
    to introduce an additional variable - Thanks !

Patch was compile-tested with. x86_64_defconfig + FIELDBUS_DEV=m,
HMS_ANYBUSS_BUS=m
(with an unrelated sparse warnings (cast to restricted __be16))

Patch is against 5.1-rc6 (localversion-next is next-20190426)

 drivers/staging/fieldbus/anybuss/host.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/fieldbus/anybuss/host.c b/drivers/staging/fieldbus/anybuss/host.c
index e34d424..6227daf 100644
--- a/drivers/staging/fieldbus/anybuss/host.c
+++ b/drivers/staging/fieldbus/anybuss/host.c
@@ -1325,11 +1325,11 @@ anybuss_host_common_probe(struct device *dev,
 	 *   interrupt came in: ready to go !
 	 */
 	reset_deassert(cd);
-	ret = wait_for_completion_timeout(&cd->card_boot, TIMEOUT);
-	if (ret == 0)
+	if (!wait_for_completion_timeout(&cd->card_boot, TIMEOUT)) {
 		ret = -ETIMEDOUT;
-	if (ret < 0)
 		goto err_reset;
+	}
+
 	/*
 	 * according to the anybus docs, we're allowed to read these
 	 * without handshaking / reserving the area
-- 
2.1.4

[PATCH] staging: fieldbus: anybus-s: force endiannes annotation

[Nicholas Mc Guire]

While the endiannes is being handled correctly sparse was unhappy with
the missing annotation as be16_to_cpu() expects a __be16. 

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
---

Problem reported by sparse

As far as I understand sparse here the __force is actually the only 
solution possible to inform sparse that the endiannes handling is ok

Patch was compile-tested with. x86_64_defconfig + FIELDBUS_DEV=m,
HMS_ANYBUSS_BUS=m

Patch is against 5.1-rc6 (localversion-next is next-20190426)

 drivers/staging/fieldbus/anybuss/host.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/fieldbus/anybuss/host.c b/drivers/staging/fieldbus/anybuss/host.c
index 6227daf..278acac 100644
--- a/drivers/staging/fieldbus/anybuss/host.c
+++ b/drivers/staging/fieldbus/anybuss/host.c
@@ -1348,7 +1348,7 @@ anybuss_host_common_probe(struct device *dev,
 	add_device_randomness(&val, 4);
 	regmap_bulk_read(cd->regmap, REG_FIELDBUS_TYPE, &fieldbus_type,
 			 sizeof(fieldbus_type));
-	fieldbus_type = be16_to_cpu(fieldbus_type);
+	fieldbus_type = be16_to_cpu((__force __be16)fieldbus_type);
 	dev_info(dev, "Fieldbus type: %04X", fieldbus_type);
 	regmap_bulk_read(cd->regmap, REG_MODULE_SW_V, val, 2);
 	dev_info(dev, "Module SW version: %02X%02X",
-- 
2.1.4

Re: [PATCH] staging: fieldbus: anybus-s: force endiannes annotation

[Sven Van Asbroeck]

Thanks for the contibution! See inline.

On Sat, Apr 27, 2019 at 10:39 PM Nicholas Mc Guire <hofrat@osadl.org> wrote:
>
> While the endiannes is being handled correctly sparse was unhappy with
> the missing annotation as be16_to_cpu() expects a __be16.

Your commit message has room for improvement here. See my remarks
on your other patch:
https://lkml.org/lkml/2019/4/28/95

>
> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
> ---
>
> Problem reported by sparse
>
> As far as I understand sparse here the __force is actually the only
> solution possible to inform sparse that the endiannes handling is ok
>
> Patch was compile-tested with. x86_64_defconfig + FIELDBUS_DEV=m,
> HMS_ANYBUSS_BUS=m
>
> Patch is against 5.1-rc6 (localversion-next is next-20190426)
>
>  drivers/staging/fieldbus/anybuss/host.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/fieldbus/anybuss/host.c b/drivers/staging/fieldbus/anybuss/host.c
> index 6227daf..278acac 100644
> --- a/drivers/staging/fieldbus/anybuss/host.c
> +++ b/drivers/staging/fieldbus/anybuss/host.c
> @@ -1348,7 +1348,7 @@ anybuss_host_common_probe(struct device *dev,
>         add_device_randomness(&val, 4);
>         regmap_bulk_read(cd->regmap, REG_FIELDBUS_TYPE, &fieldbus_type,
>                          sizeof(fieldbus_type));
> -       fieldbus_type = be16_to_cpu(fieldbus_type);
> +       fieldbus_type = be16_to_cpu((__force __be16)fieldbus_type);

Hmm... that would be cheating :)
what if you create a new local variable of type __be16?
Like so:

__be16 fieldbus_type_be;
<...>
regmap_bulk_read(cd->regmap, REG_FIELDBUS_TYPE, &fieldbus_type_be,
                          sizeof(fieldbus_type_be));
fieldbus_type = be16_to_cpu(fieldbus_type_be);

would that get sparse to shut up?

>         dev_info(dev, "Fieldbus type: %04X", fieldbus_type);
>         regmap_bulk_read(cd->regmap, REG_MODULE_SW_V, val, 2);
>         dev_info(dev, "Module SW version: %02X%02X",
> --
> 2.1.4
>

Re: [PATCH V2] staging: fieldbus: anybus-s: consolidate wait_for_completion_timeout return handling

[Sven Van Asbroeck]

Looking good, but see inline.

On Sat, Apr 27, 2019 at 10:39 PM Nicholas Mc Guire <hofrat@osadl.org> wrote:
>
> wait_for_completion_timeout() returns unsigned long (0 on timeout or
> remaining jiffies) not int - so rather than introducing an additional
> variable simply wrap the completion into an if().

Your commit message could be improved:

- the headline should make clear what this is, e.g. add functionality,
bugfix, shutting up sparse, etc. Using the verb 'fix' would be
good here.

- in case of a bugfix, it would make sense to write a short
paragraph about what can go wrong, followed by a short
paragraph outlining what the patch does to fix it.

>
> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
> ---
>
> Problem located with experimental API conformance checking cocci script
>
> V2: The original patch's logic was wrong as it was skipping the
>     fall-through if so using the fix proposed by Sven Van Asbroeck
>     <thesven73@gmail.com> - This solution also eliminates the need
>     to introduce an additional variable - Thanks !
>
> Patch was compile-tested with. x86_64_defconfig + FIELDBUS_DEV=m,
> HMS_ANYBUSS_BUS=m
> (with an unrelated sparse warnings (cast to restricted __be16))
>
> Patch is against 5.1-rc6 (localversion-next is next-20190426)
>
>  drivers/staging/fieldbus/anybuss/host.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/fieldbus/anybuss/host.c b/drivers/staging/fieldbus/anybuss/host.c
> index e34d424..6227daf 100644
> --- a/drivers/staging/fieldbus/anybuss/host.c
> +++ b/drivers/staging/fieldbus/anybuss/host.c
> @@ -1325,11 +1325,11 @@ anybuss_host_common_probe(struct device *dev,
>          *   interrupt came in: ready to go !
>          */
>         reset_deassert(cd);
> -       ret = wait_for_completion_timeout(&cd->card_boot, TIMEOUT);
> -       if (ret == 0)
> +       if (!wait_for_completion_timeout(&cd->card_boot, TIMEOUT)) {
>                 ret = -ETIMEDOUT;
> -       if (ret < 0)
>                 goto err_reset;
> +       }
> +

Nit: why add a blank line here?

>         /*
>          * according to the anybus docs, we're allowed to read these
>          * without handshaking / reserving the area
> --
> 2.1.4
>