(changing the subject and adding Arnd) Ping-Ke Shih <pkshih@xxxxxxxxxxx> writes: >> > @@ -3181,6 +3204,15 @@ static inline struct rtw89_fw_c2h_attr *RTW89_SKB_C2H_CB(struct sk_buff *skb) >> > #define RTW89_GET_MAC_C2H_REV_ACK_H2C_SEQ(c2h) \ >> > le32_get_bits(*((const __le32 *)(c2h) + 2), GENMASK(23, 16)) >> > >> > +#define RTW89_GET_MAC_BCNFLTR_RPT_MACID(c2h) \ >> > + le32_get_bits(*((const __le32 *)(c2h) + 2), GENMASK(7, 0)) >> > +#define RTW89_GET_MAC_BCNFLTR_RPT_TYPE(c2h) \ >> > + le32_get_bits(*((const __le32 *)(c2h) + 2), GENMASK(9, 8)) >> > +#define RTW89_GET_MAC_BCNFLTR_RPT_EVENT(c2h) \ >> > + le32_get_bits(*((const __le32 *)(c2h) + 2), GENMASK(11, 10)) >> > +#define RTW89_GET_MAC_BCNFLTR_RPT_MA(c2h) \ >> > + le32_get_bits(*((const __le32 *)(c2h) + 2), GENMASK(23, 16)) >> >> I have to admit that I every time I see this code pattern it makes me >> regret it. Something like what Arnd proposed back in the day would look >> so much cleaner: >> >> https://lore.kernel.org/all/CAK8P3a1rsKZZKMKFTDWgE3usX9gYKJqUvTMxSdEuZrp8BaKdaA@xxxxxxxxxxxxxx/ >> >> Of course this is just a generic comment about rtw89, and has nothing to >> do with this patchset, but it would be great if someone could take a >> look and try out Arnd's proposal. It would be good to start with just >> one or two commands and send that as an RFC to see how it looks like. >> > > I write a draft RFC here. Please see if it's in expectation. If so, I can > change all of them by another patch or RFC. > > In header file: > > #define RTW89_C2H_MAC_BCNFLTR_RPT_W2_MACID_MASK GENMASK(7, 0) > #define RTW89_C2H_MAC_BCNFLTR_RPT_W2_TYPE_MASK GENMASK(9, 8) > #define RTW89_C2H_MAC_BCNFLTR_RPT_W2_EVENT_MASK GENMASK(11, 10) > #define RTW89_C2H_MAC_BCNFLTR_RPT_W2_MA_MASK GENMASK(23, 16) > > > Access the values via le32_get_bits() in functions somewhere: > > const __le32 *c2h = skb->data; > > type = le32_get_bits(c2h[2], RTW89_C2H_MAC_BCNFLTR_RPT_W2_MACID_MASK); > sig = le32_get_bits(c2h[2], > RTW89_C2H_MAC_BCNFLTR_RPT_W2_MA_MASK) - MAX_RSSI; > event = le32_get_bits(c2h[2], RTW89_C2H_MAC_BCNFLTR_RPT_W2_EVENT_MASK); > mac_id = le32_get_bits(c2h[2], RTW89_C2H_MAC_BCNFLTR_RPT_W2_MACID_MASK); I was thinking more something towards Arnd's idea he suggests in [1]. Here's my proposal for the beacon filter command as pseudo code (so not compiled and very much buggy!) from the patch[2] which started this recent discussion. So in the header file we would have something like this: #define RTW89_C2H_BEACON_FILTER_WORD0_MACID_MASK GENMASK(7, 0) #define RTW89_C2H_BEACON_FILTER_WORD0_TYPE_MASK GENMASK(9, 8) #define RTW89_C2H_BEACON_FILTER_WORD0_EVENT_MASK GENMASK(11, 10) #define RTW89_C2H_BEACON_FILTER_WORD0_MA_MASK GENMASK(23, 16) struct rtw89_h2c_cfg_beacon_filter { __le32 word0; } static inline void rtw89_h2c_cfg_beacon_filter_set_word0(struct rtw89_h2c_cfg_beacon_filter *cmd, u32 macid, u32 type, u32 event_mask, u32 ma) { le32_replace_bits(cmd->word0, macid, RTW89_C2H_BEACON_FILTER_WORD0_MACID_MASK); le32_replace_bits(cmd->word0, type, RTW89_C2H_BEACON_FILTER_WORD0_TYPE_MASK); le32_replace_bits(cmd->word0, event, RTW89_C2H_BEACON_FILTER_WORD0_EVENT_MASK); le32_replace_bits(cmd->word0, ma, RTW89_C2H_BEACON_FILTER_WORD0_MA_MASK); } static inline u32 rtw89_h2c_cfg_beacon_filter_get_mac_id(const struct rtw89_h2c_cfg_beacon_filter *cmd) { return le32_get_bits(cmd->word0, RTW89_C2H_BEACON_FILTER_WORD0_MACID_MASK); } And an example how to use these: struct rtw89_h2c_cfg_beacon_filter *cmd; skb = rtw89_fw_h2c_alloc_skb_with_hdr(rtwdev, sizeof(*cmd)); cmd = (struct rtw89_h2c_cfg_beacon_filter *)skb->data; rtw89_h2c_cfg_beacon_filter_set_word0(cmd, 1, 2, 0, 0); I'm sure this is very buggy and I'm missing a lot but I hope you get the idea anyway. My keypoints here are: * there's a clear struct for the command (an "object" from OOP point of view), something like "__le32 *c2h" is very confusing * no casting * no pointer arithmetic * you get length with a simple "sizeof(*cmd)" Downside of course is that there's quite a lot of boilerplate code but I still consider that positives outweight the negatives. Thoughts? And I'll emphasise that this is not a blocker for anything but it would be nice to clean this up both in rtw88 and rtw89 at some point, if we can. [1] https://lore.kernel.org/all/CAK8P3a1rsKZZKMKFTDWgE3usX9gYKJqUvTMxSdEuZrp8BaKdaA@xxxxxxxxxxxxxx/ [2] https://patchwork.kernel.org/project/linux-wireless/patch/20230310034631.45299-2-pkshih@xxxxxxxxxxx/ -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
