Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: brcmfmac and unaligned sdio access on Khadas VIM3L
To:     Marek Szyprowski <m.szyprowski@samsung.com>,
        linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com,
        linux-amlogic@lists.infradead.org,
        "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>
Cc:     Arend van Spriel <aspriel@gmail.com>,
        Chung-hsien Hsu <chung-hsien.hsu@infineon.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        martin.blumenstingl@googlemail.com,
        Dmitry Lebed <lebed.dmitry@gmail.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        Wright Feng <wright.feng@infineon.com>,
        Chi-hsien Lin <chi-hsien.lin@infineon.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Franky Lin <franky.lin@broadcom.com>
References: <CGME20210209124819eucas1p29c9b481ef524a753ce79aa6ab580d0a7@eucas1p2.samsung.com>
 <967b6bfe-a612-707f-583e-c45d61acffe0@samsung.com>
 <ab81cc00-049f-67a5-bc97-417d7cd2fa44@baylibre.com>
 <1e55e4cf-3ed6-0506-2e17-b94ca8043008@samsung.com>
From:   Neil Armstrong <narmstrong@baylibre.com>
Autocrypt: addr=narmstrong@baylibre.com; prefer-encrypt=mutual; keydata=
 mQENBE1ZBs8BCAD78xVLsXPwV/2qQx2FaO/7mhWL0Qodw8UcQJnkrWmgTFRobtTWxuRx8WWP
 GTjuhvbleoQ5Cxjr+v+1ARGCH46MxFP5DwauzPekwJUD5QKZlaw/bURTLmS2id5wWi3lqVH4
 BVF2WzvGyyeV1o4RTCYDnZ9VLLylJ9bneEaIs/7cjCEbipGGFlfIML3sfqnIvMAxIMZrvcl9
 qPV2k+KQ7q+aXavU5W+yLNn7QtXUB530Zlk/d2ETgzQ5FLYYnUDAaRl+8JUTjc0CNOTpCeik
 80TZcE6f8M76Xa6yU8VcNko94Ck7iB4vj70q76P/J7kt98hklrr85/3NU3oti3nrIHmHABEB
 AAG0KE5laWwgQXJtc3Ryb25nIDxuYXJtc3Ryb25nQGJheWxpYnJlLmNvbT6JATsEEwEKACUC
 GyMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheABQJXDO2CAhkBAAoJEBaat7Gkz/iubGIH/iyk
 RqvgB62oKOFlgOTYCMkYpm2aAOZZLf6VKHKc7DoVwuUkjHfIRXdslbrxi4pk5VKU6ZP9AKsN
 NtMZntB8WrBTtkAZfZbTF7850uwd3eU5cN/7N1Q6g0JQihE7w4GlIkEpQ8vwSg5W7hkx3yQ6
 2YzrUZh/b7QThXbNZ7xOeSEms014QXazx8+txR7jrGF3dYxBsCkotO/8DNtZ1R+aUvRfpKg5
 ZgABTC0LmAQnuUUf2PHcKFAHZo5KrdO+tyfL+LgTUXIXkK+tenkLsAJ0cagz1EZ5gntuheLD
 YJuzS4zN+1Asmb9kVKxhjSQOcIh6g2tw7vaYJgL/OzJtZi6JlIW5AQ0ETVkGzwEIALyKDN/O
 GURaHBVzwjgYq+ZtifvekdrSNl8TIDH8g1xicBYpQTbPn6bbSZbdvfeQPNCcD4/EhXZuhQXM
 coJsQQQnO4vwVULmPGgtGf8PVc7dxKOeta+qUh6+SRh3vIcAUFHDT3f/Zdspz+e2E0hPV2hi
 SvICLk11qO6cyJE13zeNFoeY3ggrKY+IzbFomIZY4yG6xI99NIPEVE9lNBXBKIlewIyVlkOa
 YvJWSV+p5gdJXOvScNN1epm5YHmf9aE2ZjnqZGoMMtsyw18YoX9BqMFInxqYQQ3j/HpVgTSv
 mo5ea5qQDDUaCsaTf8UeDcwYOtgI8iL4oHcsGtUXoUk33HEAEQEAAYkBHwQYAQIACQUCTVkG
 zwIbDAAKCRAWmrexpM/4rrXiB/sGbkQ6itMrAIfnM7IbRuiSZS1unlySUVYu3SD6YBYnNi3G
 5EpbwfBNuT3H8//rVvtOFK4OD8cRYkxXRQmTvqa33eDIHu/zr1HMKErm+2SD6PO9umRef8V8
 2o2oaCLvf4WeIssFjwB0b6a12opuRP7yo3E3gTCSKmbUuLv1CtxKQF+fUV1cVaTPMyT25Od+
 RC1K+iOR0F54oUJvJeq7fUzbn/KdlhA8XPGzwGRy4zcsPWvwnXgfe5tk680fEKZVwOZKIEuJ
 C3v+/yZpQzDvGYJvbyix0lHnrCzq43WefRHI5XTTQbM0WUIBIcGmq38+OgUsMYu4NzLu7uZF
 Acmp6h8guQINBFYnf6QBEADQ+wBYa+X2n/xIQz/RUoGHf84Jm+yTqRT43t7sO48/cBW9vAn9
 GNwnJ3HRJWKATW0ZXrCr40ES/JqM1fUTfiFDB3VMdWpEfwOAT1zXS+0rX8yljgsWR1UvqyEP
 3xN0M/40Zk+rdmZKaZS8VQaXbveaiWMEmY7sBV3QvgOzB7UF2It1HwoCon5Y+PvyE3CguhBd
 9iq5iEampkMIkbA3FFCpQFI5Ai3BywkLzbA3ZtnMXR8Qt9gFZtyXvFQrB+/6hDzEPnBGZOOx
 zkd/iIX59SxBuS38LMlhPPycbFNmtauOC0DNpXCv9ACgC9tFw3exER/xQgSpDVc4vrL2Cacr
 wmQp1k9E0W+9pk/l8S1jcHx03hgCxPtQLOIyEu9iIJb27TjcXNjiInd7Uea195NldIrndD+x
 58/yU3X70qVY+eWbqzpdlwF1KRm6uV0ZOQhEhbi0FfKKgsYFgBIBchGqSOBsCbL35f9hK/JC
 6LnGDtSHeJs+jd9/qJj4WqF3x8i0sncQ/gszSajdhnWrxraG3b7/9ldMLpKo/OoihfLaCxtv
 xYmtw8TGhlMaiOxjDrohmY1z7f3rf6njskoIXUO0nabun1nPAiV1dpjleg60s3OmVQeEpr3a
 K7gR1ljkemJzM9NUoRROPaT7nMlNYQL+IwuthJd6XQqwzp1jRTGG26J97wARAQABiQM+BBgB
 AgAJBQJWJ3+kAhsCAikJEBaat7Gkz/iuwV0gBBkBAgAGBQJWJ3+kAAoJEHfc29rIyEnRk6MQ
 AJDo0nxsadLpYB26FALZsWlN74rnFXth5dQVQ7SkipmyFWZhFL8fQ9OiIoxWhM6rSg9+C1w+
 n45eByMg2b8H3mmQmyWztdI95OxSREKwbaXVapCcZnv52JRjlc3DoiiHqTZML5x1Z7lQ1T3F
 8o9sKrbFO1WQw1+Nc91+MU0MGN0jtfZ0Tvn/ouEZrSXCE4K3oDGtj3AdC764yZVq6CPigCgs
 6Ex80k6QlzCdVP3RKsnPO2xQXXPgyJPJlpD8bHHHW7OLfoR9DaBNympfcbQJeekQrTvyoASw
 EOTPKE6CVWrcQIztUp0WFTdRGgMK0cZB3Xfe6sOp24PQTHAKGtjTHNP/THomkH24Fum9K3iM
 /4Wh4V2eqGEgpdeSp5K+LdaNyNgaqzMOtt4HYk86LYLSHfFXywdlbGrY9+TqiJ+ZVW4trmui
 NIJCOku8SYansq34QzYM0x3UFRwff+45zNBEVzctSnremg1mVgrzOfXU8rt+4N1b2MxorPF8
 619aCwVP7U16qNSBaqiAJr4e5SNEnoAq18+1Gp8QsFG0ARY8xp+qaKBByWES7lRi3QbqAKZf
 yOHS6gmYo9gBmuAhc65/VtHMJtxwjpUeN4Bcs9HUpDMDVHdfeRa73wM+wY5potfQ5zkSp0Jp
 bxnv/cRBH6+c43stTffprd//4Hgz+nJcCgZKtCYIAPkUxABC85ID2CidzbraErVACmRoizhT
 KR2OiqSLW2x4xdmSiFNcIWkWJB6Qdri0Fzs2dHe8etD1HYaht1ZhZ810s7QOL7JwypO8dscN
 KTEkyoTGn6cWj0CX+PeP4xp8AR8ot4d0BhtUY34UPzjE1/xyrQFAdnLd0PP4wXxdIUuRs0+n
 WLY9Aou/vC1LAdlaGsoTVzJ2gX4fkKQIWhX0WVk41BSFeDKQ3RQ2pnuzwedLO94Bf6X0G48O
 VsbXrP9BZ6snXyHfebPnno/te5XRqZTL9aJOytB/1iUna+1MAwBxGFPvqeEUUyT+gx1l3Acl
 ZaTUOEkgIor5losDrePdPgE=
Organization: Baylibre
Message-ID: <459fb404-7370-190f-379d-751956e887df@baylibre.com>
Date:   Wed, 10 Feb 2021 09:52:11 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <1e55e4cf-3ed6-0506-2e17-b94ca8043008@samsung.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 10/02/2021 09:45, Marek Szyprowski wrote:
> Hi Neil,
> 
> On 10.02.2021 09:17, Neil Armstrong wrote:
>> On 09/02/2021 13:48, Marek Szyprowski wrote:
>>> I've noticed that the Broadcom Wifi chip performs unaligned SDIO access
>>> during the station scan on Khadas VIM3l board. This issue went unnoticed
>>> so far, because there was a workaround in the meson MMC driver, which
>>> has been recently disabled by commit e085b51c74cc ("mmc: meson-gx: check
>>> for scatterlist size alignment in block mode") from current linux-next.
>>>
>>> I can easily reproduce this issue with the following commands:
>>>
>>> # dmesg | grep brcm
>>> [   11.659351] Bluetooth: hci0: BCM4359C0 'brcm/BCM4359C0.hcd' Patch
>>> [   13.079767] brcmfmac: brcmf_fw_alloc_request: using
>>> brcm/brcmfmac4359-sdio for chip BCM4359/9
>>> [   13.527363] brcmfmac: brcmf_fw_alloc_request: using
>>> brcm/brcmfmac4359-sdio for chip BCM4359/9
>>> [   13.601269] brcmfmac: brcmf_c_process_clm_blob: no clm_blob available
>>> (err=-11), device may have limited channels available
>>> [   13.619414] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM4359/9 wl0:
>>> Mar  6 2017 10:16:06 version 9.87.51.7 (r686312) FWID 01-4dcc75d9
>>> # ifconfig wlan0 up
>>> [  208.052058] ieee80211 phy0: brcmf_dongle_roam: WLC_SET_ROAM_TRIGGER
>>> error (-52)
>>> # iw wlan0 scan >/dev/null
>>> [  218.148345] ------------[ cut here ]------------
>>> [  218.148501] unaligned sg len 504 blksize 256
>>> [  218.153712] WARNING: CPU: 1 PID: 75 at
>>> drivers/mmc/host/meson-gx-mmc.c:251
>>> meson_mmc_get_transfer_mode.isra.10+0xf8/0x130
>>> [  218.162616] Modules linked in: ipv6 brcmfmac brcmutil cfg80211
>>> dw_hdmi_cec dw_hdmi_i2s_audio hci_uart btqca btbcm bluetooth
>>> ecdh_generic ecc crct10dif_ce rfkill panfrost
>>> snd_soc_meson_axg_sound_card snd_soc_meson_card_utils gpu_sched
>>> meson_gxbb_wdt rtc_hym8563 pwm_meson meson_gxl rtc_meson_vrtc rc_khadas
>>> meson_ir reset_meson_audio_arb realtek snd_soc_meson_g12a_tohdmitx
>>> snd_soc_meson_codec_glue snd_soc_meson_axg_tdmout
>>> snd_soc_meson_axg_frddr snd_soc_meson_axg_fifo axg_audio sclk_div
>>> clk_phase mdio_mux_meson_g12a meson_dw_hdmi meson_drm meson_rng
>>> dwmac_generic snd_soc_meson_axg_tdm_interface meson_canvas rng_core
>>> dw_hdmi snd_soc_meson_axg_tdm_formatter dwmac_meson8b stmmac_platform
>>> stmmac display_connector adc_keys pcs_xpcs nvmem_meson_efuse
>>> [  218.228329] CPU: 1 PID: 75 Comm: kworker/u8:2 Not tainted
>>> 5.11.0-rc6-next-20210208 #2492
>>> [  218.236343] Hardware name: Khadas VIM3L (DT)
>>> [  218.240579] Workqueue: brcmf_wq/mmc2:0001:1 brcmf_sdio_dataworker
>>> [brcmfmac]
>>> [  218.247559] pstate: 60400009 (nZCv daif +PAN -UAO -TCO BTYPE=--)
>>> [  218.253506] pc : meson_mmc_get_transfer_mode.isra.10+0xf8/0x130
>>> [  218.259372] lr : meson_mmc_get_transfer_mode.isra.10+0xf8/0x130
>>> [  218.265237] sp : ffff80001327b870
>>> [  218.268514] x29: ffff80001327b870 x28: 0000000000000003
>>> [  218.273776] x27: 0000000000000218 x26: 0000000000000600
>>> [  218.279036] x25: ffff000003a17678 x24: 0000000000000000
>>> [  218.284296] x23: ffff8000121cfae8 x22: ffff800011b54000
>>> [  218.289559] x21: ffff80001327bb18 x20: ffff00000277d000
>>> [  218.294819] x19: ffff80001327ba40 x18: 00000002faf07f80
>>> [  218.300081] x17: 0000000000004000 x16: 0000000000000000
>>> [  218.305341] x15: 0000000000000380 x14: 0000000000000000
>>> [  218.310603] x13: 0000000000000080 x12: 0000000000000000
>>> [  218.315865] x11: 0000000000000000 x10: 0000000000001370
>>> [  218.321125] x9 : ffff00006f995258 x8 : 000000009e0e7ca7
>>> [  218.326387] x7 : ffff80001327b4a0 x6 : 0000000000000001
>>> [  218.331648] x5 : 0000000000000001 x4 : 0000000000000000
>>> [  218.336912] x3 : 0000000000000002 x2 : ffff8000121f4768
>>> [  218.342171] x1 : 42fe1bd05e5eaa00 x0 : 0000000000000000
>>> [  218.347435] Call trace:
>>> [  218.349854]  meson_mmc_get_transfer_mode.isra.10+0xf8/0x130
>>> [  218.355368]  meson_mmc_request+0x74/0xb0
>>> [  218.359250]  __mmc_start_request+0xa4/0x2b0
>>> [  218.363390]  mmc_start_request+0x80/0xa8
>>> [  218.367272]  mmc_wait_for_req+0x68/0xd8
>>> [  218.371066]  mmc_submit_one.isra.17+0x78/0x148 [brcmfmac]
>>> [  218.376416]  brcmf_sdiod_sglist_rw+0x324/0x4a8 [brcmfmac]
>>> [  218.381762]  brcmf_sdiod_recv_chain+0x70/0x140 [brcmfmac]
>>> [  218.387110]  brcmf_sdio_dataworker+0x614/0x17d0 [brcmfmac]
>>> [  218.392545]  process_one_work+0x2a8/0x728
>>> [  218.396510]  worker_thread+0x48/0x460
>>> [  218.400132]  kthread+0x134/0x160
>>> [  218.403323]  ret_from_fork+0x10/0x18
>>> [  218.406862] irq event stamp: 15834
>>> [  218.410222] hardirqs last  enabled at (15833): [<ffff800010f95804>]
>>> _raw_spin_unlock_irq+0x3c/0x80
>>> [  218.419107] hardirqs last disabled at (15834): [<ffff800010f895ac>]
>>> el1_dbg+0x24/0x50
>>> [  218.426869] softirqs last  enabled at (15828): [<ffff800010010508>]
>>> _stext+0x508/0x638
>>> [  218.434717] softirqs last disabled at (15823): [<ffff8000100952ec>]
>>> irq_exit+0x19c/0x1a8
>>> [  218.442739] ---[ end trace dfc38bb4458b4c37 ]---
>>> #
>>>
>>> Surprisingly the same commands executed on the Khadas VIM3 board with
>>> the same kernel don't trigger the warning.
>> This may be because the VIM3 (G12A & G12B) has a broken SDIO controller using
>> an internal SRAM as bounce buffer instead of the scatter/gather DMA, cf amlogic,dram-access-quirk.
> Good to know, this explains why it works without an issue on VIM3.
>>> Let me know if I can help debugging this issue.
>> Simply remove the WARN_ONCE()...
> 
> Well, that WARN is not a big issue for me. I just wanted to help fixing 
> the real issue. If I understand right, the brcmfmac driver queues 
> incorrectly prepared sd list for the given transfer mode, what should be 
> fixed there.

I think the issue comes from brcmfmac that should not provide unaligned data,
but I think it's a global issue where these kind of details aren't specified/enforced.

> 
> On the other hand, if this is just a limitation of the meson mmc 
> controller on SM1/VIM3l, then imho there should not be a WARN there and 
> maybe the mentioned 'amlogic,dram-access-quirk' could be used to fix the 
> issue on VIM3l too. I've checked and it indeed 'fixes' the issue on that 
> board.

This fix severely limits the performance so it's not a good fix here,
the only fix I see here is to remove the WARN because the fact is that the DMA cannot handle
unaligned data, and the SDIO device drivers should be fixed in order to achieve max
performance on SDIO host drivers with DMA (it's usual to not support unaligned data
when dealing with a DMA).

Neil

> 
> Best regards
>