When running the "hostapd" application on a i.MX7-based board with
an ath10k device connected via SDIO, the following warning is seen:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 489 at kernel/dma/mapping.c:427 dma_alloc_attrs+0xd0/0x114
Modules linked in: ath10k_sdio ath10k_core ath
CPU: 0 PID: 489 Comm: hostapd Not tainted 5.10.48-stable-standard #1
Hardware name: Freescale i.MX7 Dual (Device Tree)
[<c0111378>] (unwind_backtrace) from [<c010bc04>] (show_stack+0x10/0x14)
[<c010bc04>] (show_stack) from [<c0e26094>] (dump_stack+0xdc/0x104)
[<c0e26094>] (dump_stack) from [<c0125574>] (__warn+0xd8/0x114)
[<c0125574>] (__warn) from [<c0e20ecc>] (warn_slowpath_fmt+0x60/0xbc)
[<c0e20ecc>] (warn_slowpath_fmt) from [<c01b9eac>] (dma_alloc_attrs+0xd0/0x114)
[<c01b9eac>] (dma_alloc_attrs) from [<bf01373c>] (ath10k_add_interface+0x2f0/0x1094 [ath10k_core])
[<bf01373c>] (ath10k_add_interface [ath10k_core]) from [<c0d94470>] (drv_add_interface+0x88/0x2fc)
As explained by Christoph Hellwig:
"Looking at the ath10k code ar->dev is set by ath10k_core_create, which
has multiple callers.
For ath10k_pci_probe it is a pci_dev, which should always have a
dma_mask.
For ath10k_ahb_probe is a device tree probed platform_device,
which should have a dma mask.
For ath10k_sdio_probe it is a sdio_func, which from my understanding is
a virtual device can't do DMA itself.
For ath10k_snoc_probe it is a platform device with an explicit
dma_set_mask_and_coherent and above so the dma_mask is set.
For ath10k_usb_probe it is an usb device which can't do USB."
Fix the problem by not calling dma_alloc_coherent() when the device
is not DMA capable, such as SDIO and USB.
Signed-off-by: Fabio Estevam <[email protected]>
---
Hi,
I am not certain about the proper commit to include in the Fixes tag.
Any suggestions?
Thanks
drivers/net/wireless/ath/ath10k/mac.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index c272b290fa73..e85c3f107d2e 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -5576,15 +5576,17 @@ static int ath10k_add_interface(struct ieee80211_hw *hw,
if (vif->type == NL80211_IFTYPE_ADHOC ||
vif->type == NL80211_IFTYPE_MESH_POINT ||
vif->type == NL80211_IFTYPE_AP) {
- arvif->beacon_buf = dma_alloc_coherent(ar->dev,
- IEEE80211_MAX_FRAME_LEN,
- &arvif->beacon_paddr,
- GFP_ATOMIC);
- if (!arvif->beacon_buf) {
- ret = -ENOMEM;
- ath10k_warn(ar, "failed to allocate beacon buffer: %d\n",
- ret);
- goto err;
+ if (!(ar->hif.bus == ATH10K_BUS_SDIO) && !(ar->hif.bus == ATH10K_BUS_USB)) {
+ arvif->beacon_buf = dma_alloc_coherent(ar->dev,
+ IEEE80211_MAX_FRAME_LEN,
+ &arvif->beacon_paddr,
+ GFP_ATOMIC);
+ if (!arvif->beacon_buf) {
+ ret = -ENOMEM;
+ ath10k_warn(ar, "failed to allocate beacon buffer: %d\n",
+ ret);
+ goto err;
+ }
}
}
if (test_bit(ATH10K_FLAG_HW_CRYPTO_DISABLED, &ar->dev_flags))
--
2.25.1
On August 18, 2021 5:11:10 PM Fabio Estevam <[email protected]> wrote:
> When running the "hostapd" application on a i.MX7-based board with
> an ath10k device connected via SDIO, the following warning is seen:
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 489 at kernel/dma/mapping.c:427 dma_alloc_attrs+0xd0/0x114
> Modules linked in: ath10k_sdio ath10k_core ath
> CPU: 0 PID: 489 Comm: hostapd Not tainted 5.10.48-stable-standard #1
> Hardware name: Freescale i.MX7 Dual (Device Tree)
> [<c0111378>] (unwind_backtrace) from [<c010bc04>] (show_stack+0x10/0x14)
> [<c010bc04>] (show_stack) from [<c0e26094>] (dump_stack+0xdc/0x104)
> [<c0e26094>] (dump_stack) from [<c0125574>] (__warn+0xd8/0x114)
> [<c0125574>] (__warn) from [<c0e20ecc>] (warn_slowpath_fmt+0x60/0xbc)
> [<c0e20ecc>] (warn_slowpath_fmt) from [<c01b9eac>] (dma_alloc_attrs+0xd0/0x114)
> [<c01b9eac>] (dma_alloc_attrs) from [<bf01373c>]
> (ath10k_add_interface+0x2f0/0x1094 [ath10k_core])
> [<bf01373c>] (ath10k_add_interface [ath10k_core]) from [<c0d94470>]
> (drv_add_interface+0x88/0x2fc)
>
> As explained by Christoph Hellwig:
>
> "Looking at the ath10k code ar->dev is set by ath10k_core_create, which
> has multiple callers.
>
> For ath10k_pci_probe it is a pci_dev, which should always have a
> dma_mask.
>
> For ath10k_ahb_probe is a device tree probed platform_device,
> which should have a dma mask.
>
> For ath10k_sdio_probe it is a sdio_func, which from my understanding is
> a virtual device can't do DMA itself.
>
> For ath10k_snoc_probe it is a platform device with an explicit
> dma_set_mask_and_coherent and above so the dma_mask is set.
>
> For ath10k_usb_probe it is an usb device which can't do USB."
>
> Fix the problem by not calling dma_alloc_coherent() when the device
> is not DMA capable, such as SDIO and USB.
>
> Signed-off-by: Fabio Estevam <[email protected]>
> ---
> Hi,
>
> I am not certain about the proper commit to include in the Fixes tag.
>
> Any suggestions?
>
> Thanks
>
> drivers/net/wireless/ath/ath10k/mac.c | 20 +++++++++++---------
> 1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/mac.c
> b/drivers/net/wireless/ath/ath10k/mac.c
> index c272b290fa73..e85c3f107d2e 100644
> --- a/drivers/net/wireless/ath/ath10k/mac.c
> +++ b/drivers/net/wireless/ath/ath10k/mac.c
> @@ -5576,15 +5576,17 @@ static int ath10k_add_interface(struct ieee80211_hw
> *hw,
> if (vif->type == NL80211_IFTYPE_ADHOC ||
> vif->type == NL80211_IFTYPE_MESH_POINT ||
> vif->type == NL80211_IFTYPE_AP) {
> - arvif->beacon_buf = dma_alloc_coherent(ar->dev,
> - IEEE80211_MAX_FRAME_LEN,
> - &arvif->beacon_paddr,
> - GFP_ATOMIC);
> - if (!arvif->beacon_buf) {
> - ret = -ENOMEM;
> - ath10k_warn(ar, "failed to allocate beacon buffer: %d\n",
> - ret);
> - goto err;
> + if (!(ar->hif.bus == ATH10K_BUS_SDIO) && !(ar->hif.bus == ATH10K_BUS_USB)) {
Does this mean you can not really setup a beaconing interface type for SDIO
and USB?
Regards,
Arend
>> Fix the problem by not calling dma_alloc_coherent() when the device
>> is not DMA capable, such as SDIO and USB.
>>
ath10k calls dma_alloc_coherent multiple places including
ath10k_htt_rx_alloc.
Do SDIO and USB not use such data path function at all?
Thanks,
Peter
Hi Peter,
On Wed, Aug 18, 2021 at 2:35 PM Peter Oh <[email protected]> wrote:
>
>
> >> Fix the problem by not calling dma_alloc_coherent() when the device
> >> is not DMA capable, such as SDIO and USB.
> >>
> ath10k calls dma_alloc_coherent multiple places including
> ath10k_htt_rx_alloc.
>
> Do SDIO and USB not use such data path function at all?
Good point! Maybe I am not just hitting these paths on my simple tests.
Kalle,
How should we handle this?
Thanks
Hi Arend,
On Wed, Aug 18, 2021 at 1:51 PM Arend van Spriel <[email protected]> wrote:
> Does this mean you can not really setup a beaconing interface type for SDIO
> and USB?
As per the debug message below:
ath10k_dbg(ar, ATH10K_DBG_MAC, "mac vdev create %d (add interface)
type %d subtype %d bcnmode %s\n",
arvif->vdev_id, arvif->vdev_type, arvif->vdev_subtype,
arvif->beacon_buf ? "single-buf" : "per-skb");
If arvif->beacon_buf is NULL then it will be a "per-skb" beacon mode.
Thanks
Hi Peter,
On Wed, Aug 18, 2021 at 2:35 PM Peter Oh <[email protected]> wrote:
>
>
> >> Fix the problem by not calling dma_alloc_coherent() when the device
> >> is not DMA capable, such as SDIO and USB.
> >>
> ath10k calls dma_alloc_coherent multiple places including
> ath10k_htt_rx_alloc.
>
> Do SDIO and USB not use such data path function at all?
Now that I look closer: no, SDIO and USB do not reach the
dma_alloc_coherent() inside
ath10k_htt_rx_alloc.
drivers/net/wireless/ath/ath10k/usb.c and
drivers/net/wireless/ath/ath10k/sdio.c both set:
bus_params.dev_type = ATH10K_DEV_TYPE_HL;
ath10k_htt_rx_alloc() has:
if (ar->bus_param.dev_type == ATH10K_DEV_TYPE_HL)
return 0;
So it returns early in the USB and SDIO cases and does not call
dma_alloc_coherent().
Thanks