On Mon, 2009-11-30 at 12:39 +0200, Kalle Valo wrote:
> From: Kalle Valo <kalle.valo@xxxxxxxxx>
>
> The payload alignment warning enabled by MAC80211_DEBUG_PACKET_ALIGNMENT is
> difficult. To fix it, a firmware change is needed but in most cases that's
> very difficult. So the benefit from the warning is low and most probably
> it just creates more confusion for people who just enable all warnings
> (like it did for me).
>
> Remove the unaligned IP payload warning and the kconfig option. But
> leave the unlialigned packet warning, it will be enabled with
> MAC80211_VERBOSE_DEBUG.
>
> Signed-off-by: Kalle Valo <kalle.valo@xxxxxxxxx>
Thanks.
Acked-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> ---
> net/mac80211/Kconfig | 12 ------------
> net/mac80211/rx.c | 27 +++++++--------------------
> 2 files changed, 7 insertions(+), 32 deletions(-)
>
> diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig
> index a10d508..a952b7f 100644
> --- a/net/mac80211/Kconfig
> +++ b/net/mac80211/Kconfig
> @@ -96,18 +96,6 @@ menuconfig MAC80211_DEBUG_MENU
> ---help---
> This option collects various mac80211 debug settings.
>
> -config MAC80211_DEBUG_PACKET_ALIGNMENT
> - bool "Enable packet alignment debugging"
> - depends on MAC80211_DEBUG_MENU
> - ---help---
> - This option is recommended for driver authors and strongly
> - discouraged for everybody else, it will trigger a warning
> - when a driver hands mac80211 a buffer that is aligned in
> - a way that will cause problems with the IP stack on some
> - architectures.
> -
> - Say N unless you're writing a mac80211 based driver.
> -
> config MAC80211_NOINLINE
> bool "Do not inline TX/RX handlers"
> depends on MAC80211_DEBUG_MENU
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index 57b8a0a..18a0248 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -361,7 +361,9 @@ static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
> * boundary. In the case of regular frames, this simply means aligning the
> * payload to a four-byte boundary (because either the IP header is directly
> * contained, or IV/RFC1042 headers that have a length divisible by four are
> - * in front of it).
> + * in front of it). If the payload data is not properly aligned and the
> + * architecture doesn't support efficient unaligned operations, mac80211
> + * will align the data.
> *
> * With A-MSDU frames, however, the payload data address must yield two modulo
> * four because there are 14-byte 802.3 headers within the A-MSDU frames that
> @@ -375,25 +377,10 @@ static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
> */
> static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
> {
> - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
> - int hdrlen;
> -
> -#ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
> - return;
> +#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
> + WARN_ONCE((unsigned long)rx->skb->data & 1,
> + "unaligned packet at 0x%p\n", rx->skb->data);
> #endif
> -
> - if (WARN_ONCE((unsigned long)rx->skb->data & 1,
> - "unaligned packet at 0x%p\n", rx->skb->data))
> - return;
> -
> - if (!ieee80211_is_data_present(hdr->frame_control))
> - return;
> -
> - hdrlen = ieee80211_hdrlen(hdr->frame_control);
> - if (rx->flags & IEEE80211_RX_AMSDU)
> - hdrlen += ETH_HLEN;
> - WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
> - "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
> }
>
>
> @@ -1512,7 +1499,7 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
> if (skb) {
> int align __maybe_unused;
>
> -#if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
> +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
> /*
> * 'align' will only take the values 0 or 2 here
> * since all frames are required to be aligned
>
>
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