Re: [PATCH] staging: greybus: fix gb_loopback_stats_attrs definition

Alex Elder
2021-05-14T18:53:55Z

On 5/14/21 10:56 AM, Joe Perches wrote:
> On Fri, 2021-05-14 at 17:30 +0200, Greg KH wrote:
>> On Fri, May 14, 2021 at 08:42:16PM +0530, Shreyansh Chouhan wrote:
> []
>>> I didn't look at how/where was the macro called and missed a very
>>> obvious error. Now that I have looked at it, the only way I can think of
>>> fixing this is changing the macro to a (inline?) function. Will
>>> that be a desirable change?
>>
>> No, it can't be a function, the code is fine as-is, checkpatch is just a
>> perl script and does not always know what needs to be done.
>
> true.
>
> perhaps better though to rename these declaring macros to start with declare_

I don't disagree with your suggestion, but it's not clear it
would have prevented submission of the erroneous initial patch
(nor future ones from people who blindly follow checkpatch.pl
suggestions).

-Alex

PS Lots of negatives in that sentence.

> Something like this:
> (with miscellaneous realigning of the macros line ending continuations \)
> ---
> drivers/staging/greybus/loopback.c | 72 +++++++++++++++++++-------------------
> 1 file changed, 36 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
> index 2471448ba42a..dc399792f35f 100644
> --- a/drivers/staging/greybus/loopback.c
> +++ b/drivers/staging/greybus/loopback.c
> @@ -119,18 +119,18 @@ module_param(kfifo_depth, uint, 0444);
> #define GB_LOOPBACK_US_WAIT_MAX 1000000
>
> /* interface sysfs attributes */
> -#define gb_loopback_ro_attr(field) \
> -static ssize_t field##_show(struct device *dev, \
> +#define declare_gb_loopback_ro_attr(field) \
> +static ssize_t field##_show(struct device *dev, \
> struct device_attribute *attr, \
> char *buf) \
> { \
> struct gb_loopback *gb = dev_get_drvdata(dev); \
> - return sprintf(buf, "%u\n", gb->field); \
> + return sprintf(buf, "%u\n", gb->field); \
> } \
> static DEVICE_ATTR_RO(field)
>
> -#define gb_loopback_ro_stats_attr(name, field, type) \
> -static ssize_t name##_##field##_show(struct device *dev, \
> +#define declare_gb_loopback_ro_stats_attr(name, field, type) \
> +static ssize_t name##_##field##_show(struct device *dev, \
> struct device_attribute *attr, \
> char *buf) \
> { \
> @@ -142,8 +142,8 @@ static ssize_t name##_##field##_show(struct device *dev, \
> } \
> static DEVICE_ATTR_RO(name##_##field)
>
> -#define gb_loopback_ro_avg_attr(name) \
> -static ssize_t name##_avg_show(struct device *dev, \
> +#define declare_gb_loopback_ro_avg_attr(name) \
> +static ssize_t name##_avg_show(struct device *dev, \
> struct device_attribute *attr, \
> char *buf) \
> { \
> @@ -151,8 +151,8 @@ static ssize_t name##_avg_show(struct device *dev, \
> struct gb_loopback *gb; \
> u64 avg, rem; \
> u32 count; \
> - gb = dev_get_drvdata(dev); \
> - stats = &gb->name; \
> + gb = dev_get_drvdata(dev); \
> + stats = &gb->name; \
> count = stats->count ? stats->count : 1; \
> avg = stats->sum + count / 2000000; /* round closest */ \
> rem = do_div(avg, count); \
> @@ -162,12 +162,12 @@ static ssize_t name##_avg_show(struct device *dev, \
> } \
> static DEVICE_ATTR_RO(name##_avg)
>
> -#define gb_loopback_stats_attrs(field) \
> - gb_loopback_ro_stats_attr(field, min, u); \
> - gb_loopback_ro_stats_attr(field, max, u); \
> - gb_loopback_ro_avg_attr(field)
> +#define declare_gb_loopback_stats_attrs(field) \
> + declare_gb_loopback_ro_stats_attr(field, min, u); \
> + declare_gb_loopback_ro_stats_attr(field, max, u); \
> + declare_gb_loopback_ro_avg_attr(field)
>
> -#define gb_loopback_attr(field, type) \
> +#define declare_gb_loopback_attr(field, type) \
> static ssize_t field##_show(struct device *dev, \
> struct device_attribute *attr, \
> char *buf) \
> @@ -193,8 +193,8 @@ static ssize_t field##_store(struct device *dev, \
> } \
> static DEVICE_ATTR_RW(field)
>
> -#define gb_dev_loopback_ro_attr(field, conn) \
> -static ssize_t field##_show(struct device *dev, \
> +#define declare_gb_dev_loopback_ro_attr(field, conn) \
> +static ssize_t field##_show(struct device *dev, \
> struct device_attribute *attr, \
> char *buf) \
> { \
> @@ -203,7 +203,7 @@ static ssize_t field##_show(struct device *dev, \
> } \
> static DEVICE_ATTR_RO(field)
>
> -#define gb_dev_loopback_rw_attr(field, type) \
> +#define declare_gb_dev_loopback_rw_attr(field, type) \
> static ssize_t field##_show(struct device *dev, \
> struct device_attribute *attr, \
> char *buf) \
> @@ -223,7 +223,7 @@ static ssize_t field##_store(struct device *dev, \
> if (ret != 1) \
> len = -EINVAL; \
> else \
> - gb_loopback_check_attr(gb); \
> + gb_loopback_check_attr(gb); \
> mutex_unlock(&gb->mutex); \
> return len; \
> } \
> @@ -268,26 +268,26 @@ static void gb_loopback_check_attr(struct gb_loopback *gb)
> }
>
> /* Time to send and receive one message */
> -gb_loopback_stats_attrs(latency);
> +declare_gb_loopback_stats_attrs(latency);
> /* Number of requests sent per second on this cport */
> -gb_loopback_stats_attrs(requests_per_second);
> +declare_gb_loopback_stats_attrs(requests_per_second);
> /* Quantity of data sent and received on this cport */
> -gb_loopback_stats_attrs(throughput);
> +declare_gb_loopback_stats_attrs(throughput);
> /* Latency across the UniPro link from APBridge's perspective */
> -gb_loopback_stats_attrs(apbridge_unipro_latency);
> +declare_gb_loopback_stats_attrs(apbridge_unipro_latency);
> /* Firmware induced overhead in the GPBridge */
> -gb_loopback_stats_attrs(gbphy_firmware_latency);
> +declare_gb_loopback_stats_attrs(gbphy_firmware_latency);
>
> /* Number of errors encountered during loop */
> -gb_loopback_ro_attr(error);
> +declare_gb_loopback_ro_attr(error);
> /* Number of requests successfully completed async */
> -gb_loopback_ro_attr(requests_completed);
> +declare_gb_loopback_ro_attr(requests_completed);
> /* Number of requests timed out async */
> -gb_loopback_ro_attr(requests_timedout);
> +declare_gb_loopback_ro_attr(requests_timedout);
> /* Timeout minimum in useconds */
> -gb_loopback_ro_attr(timeout_min);
> +declare_gb_loopback_ro_attr(timeout_min);
> /* Timeout minimum in useconds */
> -gb_loopback_ro_attr(timeout_max);
> +declare_gb_loopback_ro_attr(timeout_max);
>
> /*
> * Type of loopback message to send based on protocol type definitions
> @@ -297,21 +297,21 @@ gb_loopback_ro_attr(timeout_max);
> * payload returned in response)
> * 4 => Send a sink message (message with payload, no payload in response)
> */
> -gb_dev_loopback_rw_attr(type, d);
> +declare_gb_dev_loopback_rw_attr(type, d);
> /* Size of transfer message payload: 0-4096 bytes */
> -gb_dev_loopback_rw_attr(size, u);
> +declare_gb_dev_loopback_rw_attr(size, u);
> /* Time to wait between two messages: 0-1000 ms */
> -gb_dev_loopback_rw_attr(us_wait, d);
> +declare_gb_dev_loopback_rw_attr(us_wait, d);
> /* Maximum iterations for a given operation: 1-(2^32-1), 0 implies infinite */
> -gb_dev_loopback_rw_attr(iteration_max, u);
> +declare_gb_dev_loopback_rw_attr(iteration_max, u);
> /* The current index of the for (i = 0; i < iteration_max; i++) loop */
> -gb_dev_loopback_ro_attr(iteration_count, false);
> +declare_gb_dev_loopback_ro_attr(iteration_count, false);
> /* A flag to indicate synchronous or asynchronous operations */
> -gb_dev_loopback_rw_attr(async, u);
> +declare_gb_dev_loopback_rw_attr(async, u);
> /* Timeout of an individual asynchronous request */
> -gb_dev_loopback_rw_attr(timeout, u);
> +declare_gb_dev_loopback_rw_attr(timeout, u);
> /* Maximum number of in-flight operations before back-off */
> -gb_dev_loopback_rw_attr(outstanding_operations_max, u);
> +declare_gb_dev_loopback_rw_attr(outstanding_operations_max, u);
>
> static struct attribute *loopback_attrs[] = {
> &dev_attr_latency_min.attr,
>