From 997bc71a3601b25dbbe3ac75b77b4f49582c0ae5 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Tue, 4 Mar 2014 14:18:42 +0100 Subject: [PATCH] iwl4965: disable 8K A-MSDU by default iwlegacy version of this iwlwifi patch: commit aed7d9ac1836defe033b561f4306e39014ac56fd Author: Emmanuel Grumbach Date: Wed Feb 20 11:33:00 2013 +0200 iwlwifi: disable 8K A-MSDU by default Supporting 8K A-MSDU means that we need to allocate order 1 pages for every Rx packet. Even when there is no traffic. This adds stress on the memory manager. The handling of compound pages is also less trivial for the memory manager and not using them will make the allocation code run faster although I didn't really measure. Eric also pointed out that having huge buffers with little data in them is not very nice towards the TCP stack since the truesize of the skb is huge. This doesn't allow TCP to have a big Rx window. See https://patchwork.kernel.org/patch/2167711/ for details. Note that very few vendors will actually send A-MSDU. Disable this feature by default. Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg Signed-off-by: Stanislaw Gruszka Signed-off-by: John W. Linville --- drivers/net/wireless/iwlegacy/4965-mac.c | 3 +-- drivers/net/wireless/iwlegacy/common.h | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/iwlegacy/4965-mac.c b/drivers/net/wireless/iwlegacy/4965-mac.c index 50673f7e30bc..888ad5c74639 100644 --- a/drivers/net/wireless/iwlegacy/4965-mac.c +++ b/drivers/net/wireless/iwlegacy/4965-mac.c @@ -92,7 +92,6 @@ il4965_check_abort_status(struct il_priv *il, u8 frame_count, u32 status) * EEPROM */ struct il_mod_params il4965_mod_params = { - .amsdu_size_8K = 1, .restart_fw = 1, /* the rest are 0 by default */ }; @@ -6866,6 +6865,6 @@ module_param_named(11n_disable, il4965_mod_params.disable_11n, int, S_IRUGO); MODULE_PARM_DESC(11n_disable, "disable 11n functionality"); module_param_named(amsdu_size_8K, il4965_mod_params.amsdu_size_8K, int, S_IRUGO); -MODULE_PARM_DESC(amsdu_size_8K, "enable 8K amsdu size"); +MODULE_PARM_DESC(amsdu_size_8K, "enable 8K amsdu size (default 0 [disabled])"); module_param_named(fw_restart, il4965_mod_params.restart_fw, int, S_IRUGO); MODULE_PARM_DESC(fw_restart, "restart firmware in case of error"); diff --git a/drivers/net/wireless/iwlegacy/common.h b/drivers/net/wireless/iwlegacy/common.h index 13145ad2c0db..dfb13c70efe8 100644 --- a/drivers/net/wireless/iwlegacy/common.h +++ b/drivers/net/wireless/iwlegacy/common.h @@ -1598,7 +1598,7 @@ struct il_mod_params { int disable_hw_scan; /* def: 0 = use h/w scan */ int num_of_queues; /* def: HW dependent */ int disable_11n; /* def: 0 = 11n capabilities enabled */ - int amsdu_size_8K; /* def: 1 = enable 8K amsdu size */ + int amsdu_size_8K; /* def: 0 = disable 8K amsdu size */ int antenna; /* def: 0 = both antennas (use diversity) */ int restart_fw; /* def: 1 = restart firmware */ };