Hi Sedat, On Thu, 2010-05-13 at 15:58 -0700, Sedat Dilek wrote: > Sorry, I was confused by the comments in [1] and I am especially > interested in the internal scans stuff: > > Port following patch to 3945. Yeah ... in retrospect that commit message could benefit with the details on why it is needed. Sorry for the confusion. It is indeed a port of the iwlagn patch since iwlagn used internal scanning long before iwl3945 and the race was thus fixed there first. The same fix was not done at that time for iwl3945 since it (iwl3945) was not using internal scanning. > > "commit 90c4162ff59a3281b6d2f7206740be6217bd6758 > Author: Johannes Berg <johannes.berg@xxxxxxxxx> > Date: Wed Apr 7 00:21:36 2010 -0700 > iwlwifi: fix scan races" > > The above mentionned patch is already accepted to upstream (2.6.34) > [2] and iwlagn _is_ already using internal scans. Right. > So why is iwl3945 > different in 2.6.34 especially in that case? In 2.6.34 iwl3945 never calls RF reset, which triggers an internal scan. In 2.6.34 iwlagn calls RF reset if the information received in statistics notification warrants it. This feature is added to iwl3945 in 2.6.35 with [3]. > On first sight, I can't see the correlation of "iwl3945: add plcp > error checking" [3] and "iwl3945: fix scan races" [1]. Note that [3] adds a value (and implementation behind that value) to the check_plcp_health function pointer, which is called from iwl_recover_from_statistics() which is for the first time made available to iwl3945 in this patch also (see changes to iwl-rx.c). It is iwl_recover_from_statistics() that uses statistic information (now available via the new check_plcp_health function) to decide if an RF reset is needed. Before this patch iwl3945 merely recorded received statistics, it never made decisions based on the information contained in it. This patch introduces the logic to use statistics information to decide if an RF reset is needed and will trigger and RF reset if needed. Now, an RF reset is done via an internal scan and before [3] there was nothing in iwl3945 that triggered an internal scan. We do have issues with internal scanning, but they were not all addressed for iwl3945 since iwl3945 was not using internal scanning. With [3] we introduced usage of internal scanning so needed to make sure that the internal scan races are fixed for it also which was done with [1]. > [1] https://patchwork.kernel.org/patch/98326/ > [2] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=88be026490ed89c2ffead81a52531fbac5507e01 > [3] http://git.kernel.org/?p=linux/kernel/git/iwlwifi/iwlwifi-2.6.git;a=commit;h=a29576a7844326c5223f4d4adbfd3f4d64173d4c Reinette -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
