Re: [PATCH 6/6] wlan-ng: clean up reused macros

From: Dan Carpenter
Date: Tue Jan 19 2021 - 05:01:26 EST


On Mon, Jan 18, 2021 at 02:09:56AM +0100, Johannes Czekay wrote:
> This patch cleans up two "macro argument reuse" warnings by checkpatch.
> This should also make the code much more readable.
>
> Signed-off-by: Johannes Czekay <johannes.czekay@xxxxxx>
> Co-developed-by: Nicolai Fischer <nicolai.fischer@xxxxxx>
> Signed-off-by: Nicolai Fischer <nicolai.fischer@xxxxxx>
> ---
> drivers/staging/wlan-ng/p80211metastruct.h | 18 +-------
> drivers/staging/wlan-ng/prism2mgmt.c | 48 ++++++----------------
> 2 files changed, 14 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/staging/wlan-ng/p80211metastruct.h b/drivers/staging/wlan-ng/p80211metastruct.h
> index 4adc64580185..e963227f797c 100644
> --- a/drivers/staging/wlan-ng/p80211metastruct.h
> +++ b/drivers/staging/wlan-ng/p80211metastruct.h
> @@ -114,22 +114,8 @@ struct p80211msg_dot11req_scan_results {
> struct p80211item_uint32 cfpollreq;
> struct p80211item_uint32 privacy;
> struct p80211item_uint32 capinfo;
> - struct p80211item_uint32 basicrate1;
> - struct p80211item_uint32 basicrate2;
> - struct p80211item_uint32 basicrate3;
> - struct p80211item_uint32 basicrate4;
> - struct p80211item_uint32 basicrate5;
> - struct p80211item_uint32 basicrate6;
> - struct p80211item_uint32 basicrate7;
> - struct p80211item_uint32 basicrate8;
> - struct p80211item_uint32 supprate1;
> - struct p80211item_uint32 supprate2;
> - struct p80211item_uint32 supprate3;
> - struct p80211item_uint32 supprate4;
> - struct p80211item_uint32 supprate5;
> - struct p80211item_uint32 supprate6;
> - struct p80211item_uint32 supprate7;
> - struct p80211item_uint32 supprate8;
> + struct p80211item_uint32 basicrate[8];
> + struct p80211item_uint32 supprate[8];
> } __packed;
>
> struct p80211msg_dot11req_start {
> diff --git a/drivers/staging/wlan-ng/prism2mgmt.c b/drivers/staging/wlan-ng/prism2mgmt.c
> index 1bd36dc2b7ff..8540c3336907 100644
> --- a/drivers/staging/wlan-ng/prism2mgmt.c
> +++ b/drivers/staging/wlan-ng/prism2mgmt.c
> @@ -388,6 +388,7 @@ int prism2mgmt_scan_results(struct wlandevice *wlandev, void *msgp)
> struct hfa384x_hscan_result_sub *item = NULL;
>
> int count;
> + int i;
>
> req = msgp;
>
> @@ -437,42 +438,17 @@ int prism2mgmt_scan_results(struct wlandevice *wlandev, void *msgp)
> if (item->supprates[count] == 0)
> break;
>
> -#define REQBASICRATE(N) \
> - do { \
> - if ((count >= (N)) && DOT11_RATE5_ISBASIC_GET( \
> - item->supprates[(N) - 1])) { \
> - req->basicrate ## N .data = item->supprates[(N) - 1]; \
> - req->basicrate ## N .status = \
> - P80211ENUM_msgitem_status_data_ok; \
> - } \
> - } while (0)
> -
> - REQBASICRATE(1);
> - REQBASICRATE(2);
> - REQBASICRATE(3);
> - REQBASICRATE(4);
> - REQBASICRATE(5);
> - REQBASICRATE(6);
> - REQBASICRATE(7);
> - REQBASICRATE(8);
> -
> -#define REQSUPPRATE(N) \
> - do { \
> - if (count >= (N)) { \
> - req->supprate ## N .data = item->supprates[(N) - 1]; \
> - req->supprate ## N .status = \
> - P80211ENUM_msgitem_status_data_ok; \
> - } \
> - } while (0)
> -
> - REQSUPPRATE(1);
> - REQSUPPRATE(2);
> - REQSUPPRATE(3);
> - REQSUPPRATE(4);
> - REQSUPPRATE(5);
> - REQSUPPRATE(6);
> - REQSUPPRATE(7);
> - REQSUPPRATE(8);
> + for (i = 0; i < 8; i++) {
> + if (count > 1) {

This should be "i" instead of "1". And conditions are more readable if
you put the part that changes first "if (variable < limit)" to avoid
backwards think.

if (i < count) {

Or you could reverse it the other way:

if (i >= count)
break;

> + if (DOT11_RATE5_ISBASIC_GET(item->supprates[i])) {
> + req->basicrate[i].data = item->supprates[i];
> + req->basicrate[i].status = P80211ENUM_msgitem_status_data_ok;
> + }
> +
> + req->supprate[i].data = item->supprates[i];
> + req->supprate[i].status = P80211ENUM_msgitem_status_data_ok;
> + }
> + }

It's sort of surprising that we can change how we write this information
but we don't have to change how it is read. I guess presumably it's
just dumped as hex to debugfs or something like that... Who knows. :/

regards,
dan carpenter