2019-05-17 23:19:08

by Doug Anderson

[permalink] [raw]
Subject: [PATCH 1/3] brcmfmac: re-enable command decode in sdio_aos for BRCM 4354

In commit 29f6589140a1 ("brcmfmac: disable command decode in
sdio_aos") we disabled something called "command decode in sdio_aos"
for a whole bunch of Broadcom SDIO WiFi parts.

After that patch landed I find that my kernel log on
rk3288-veyron-minnie and rk3288-veyron-speedy is filled with:
brcmfmac: brcmf_sdio_bus_sleep: error while changing bus sleep state -110

This seems to happen every time the Broadcom WiFi transitions out of
sleep mode. Reverting the part of the commit that affects the WiFi on
my boards fixes the problem for me, so that's what this patch does.

Note that, in general, the justification in the original commit seemed
a little weak. It looked like someone was testing on a SD card
controller that would sometimes die if there were CRC errors on the
bus. This used to happen back in early days of dw_mmc (the controller
on my boards), but we fixed it. Disabling a feature on all boards
just because one SD card controller is broken seems bad. ...so
instead of just this patch possibly the right thing to do is to fully
revert the original commit.

Fixes: 29f6589140a1 ("brcmfmac: disable command decode in sdio_aos")
Signed-off-by: Douglas Anderson <[email protected]>
---

drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index 22b73da42822..3fd2d58a3c88 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -3378,8 +3378,7 @@ static bool brcmf_sdio_aos_no_decode(struct brcmf_sdio *bus)
if (bus->ci->chip == CY_CC_43012_CHIP_ID ||
bus->ci->chip == CY_CC_4373_CHIP_ID ||
bus->ci->chip == BRCM_CC_4339_CHIP_ID ||
- bus->ci->chip == BRCM_CC_4345_CHIP_ID ||
- bus->ci->chip == BRCM_CC_4354_CHIP_ID)
+ bus->ci->chip == BRCM_CC_4345_CHIP_ID)
return true;
else
return false;
--
2.21.0.1020.gf2820cf01a-goog


2019-05-20 08:21:22

by Arend Van Spriel

[permalink] [raw]
Subject: Re: [PATCH 1/3] brcmfmac: re-enable command decode in sdio_aos for BRCM 4354



On 5/18/2019 12:54 AM, Douglas Anderson wrote:
> In commit 29f6589140a1 ("brcmfmac: disable command decode in
> sdio_aos") we disabled something called "command decode in sdio_aos"
> for a whole bunch of Broadcom SDIO WiFi parts.
>
> After that patch landed I find that my kernel log on
> rk3288-veyron-minnie and rk3288-veyron-speedy is filled with:
> brcmfmac: brcmf_sdio_bus_sleep: error while changing bus sleep state -110
>
> This seems to happen every time the Broadcom WiFi transitions out of
> sleep mode. Reverting the part of the commit that affects the WiFi on
> my boards fixes the problem for me, so that's what this patch does.

This sounds very similar to the issue we had during integration of wifi
on rk3288 chromebooks years ago.

> Note that, in general, the justification in the original commit seemed
> a little weak. It looked like someone was testing on a SD card
> controller that would sometimes die if there were CRC errors on the
> bus. This used to happen back in early days of dw_mmc (the controller
> on my boards), but we fixed it. Disabling a feature on all boards
> just because one SD card controller is broken seems bad. ...so
> instead of just this patch possibly the right thing to do is to fully
> revert the original commit.

I am leaning towards a full revert, but let's wait for more background info.

Regards,
Arend

2019-05-20 18:23:54

by Doug Anderson

[permalink] [raw]
Subject: Re: [PATCH 1/3] brcmfmac: re-enable command decode in sdio_aos for BRCM 4354

Hi,

On Mon, May 20, 2019 at 1:09 AM Arend Van Spriel
<[email protected]> wrote:
>
> On 5/18/2019 12:54 AM, Douglas Anderson wrote:
> > In commit 29f6589140a1 ("brcmfmac: disable command decode in
> > sdio_aos") we disabled something called "command decode in sdio_aos"
> > for a whole bunch of Broadcom SDIO WiFi parts.
> >
> > After that patch landed I find that my kernel log on
> > rk3288-veyron-minnie and rk3288-veyron-speedy is filled with:
> > brcmfmac: brcmf_sdio_bus_sleep: error while changing bus sleep state -110
> >
> > This seems to happen every time the Broadcom WiFi transitions out of
> > sleep mode. Reverting the part of the commit that affects the WiFi on
> > my boards fixes the problem for me, so that's what this patch does.
>
> This sounds very similar to the issue we had during integration of wifi
> on rk3288 chromebooks years ago.

I'm working on those same Chromebooks. ;-) I'm working on trying to
make them well on newer kernels.

...but I guess you're saying that the problem faced by the people who
wanted commit 29f6589140a1 ("brcmfmac: disable command decode in
sdio_aos") are similar to the problems we saw in the past on those
Chromebooks. I'd tend to agree. In general it's difficult to get a
SD Host Controller to be fully robust in the fact of any/all errors on
the bus. While dw_mmc is pretty robust these days I'm assuming that
some other host controllers aren't.


> > Note that, in general, the justification in the original commit seemed
> > a little weak. It looked like someone was testing on a SD card
> > controller that would sometimes die if there were CRC errors on the
> > bus. This used to happen back in early days of dw_mmc (the controller
> > on my boards), but we fixed it. Disabling a feature on all boards
> > just because one SD card controller is broken seems bad. ...so
> > instead of just this patch possibly the right thing to do is to fully
> > revert the original commit.
>
> I am leaning towards a full revert, but let's wait for more background info.

I'd be fine with a full revert too. Presumably that will break
someone but maybe they need to come up with a better solution?

-Doug

2019-06-04 16:10:19

by Doug Anderson

[permalink] [raw]
Subject: Re: [PATCH 1/3] brcmfmac: re-enable command decode in sdio_aos for BRCM 4354

Hi,

On Mon, Jun 3, 2019 at 8:20 PM Wright Feng <[email protected]> wrote:
>
> On 2019/5/29 上午 12:11, Arend Van Spriel wrote:
> > On May 28, 2019 6:09:21 PM Arend Van Spriel
> > <[email protected]> wrote:
> >
> >> On May 28, 2019 5:52:10 PM Doug Anderson <[email protected]> wrote:
> >>
> >>> Hi,
> >>>
> >>> On Tue, May 28, 2019 at 5:18 AM Kalle Valo <[email protected]> wrote:
> >>>>
> >>>> Douglas Anderson <[email protected]> wrote:
> >>>>
> >>>> > In commit 29f6589140a1 ("brcmfmac: disable command decode in
> >>>> > sdio_aos") we disabled something called "command decode in sdio_aos"
> >>>> > for a whole bunch of Broadcom SDIO WiFi parts.
> >>>> >
> >>>> > After that patch landed I find that my kernel log on
> >>>> > rk3288-veyron-minnie and rk3288-veyron-speedy is filled with:
> >>>> > brcmfmac: brcmf_sdio_bus_sleep: error while changing bus sleep
> >>>> state -110
> >>>> >
> >>>> > This seems to happen every time the Broadcom WiFi transitions out of
> >>>> > sleep mode. Reverting the part of the commit that affects the
> >>>> WiFi on
> >>>> > my boards fixes the problem for me, so that's what this patch does.
> >>>> >
> >>>> > Note that, in general, the justification in the original commit
> >>>> seemed
> >>>> > a little weak. It looked like someone was testing on a SD card
> >>>> > controller that would sometimes die if there were CRC errors on the
> >>>> > bus. This used to happen back in early days of dw_mmc (the
> >>>> controller
> >>>> > on my boards), but we fixed it. Disabling a feature on all boards
> >>>> > just because one SD card controller is broken seems bad. ...so
> >>>> > instead of just this patch possibly the right thing to do is to fully
> >>>> > revert the original commit.
> >>>> >
> Since the commit 29f6589140a1 ("brcmfmac: disable command decode in
> sdio_aos") causes the regression on other SD card controller, it is
> better to revert it as you mentioned.
> Actually, without the commit, we hit MMC timeout(-110) and hanged
> instead of CRC error in our test.

Any chance I can convince you to provide some official tags like
Reviewed-by or Tested-by on the revert?

> Would you please share the analysis of
> dw_mmc issue which you fixed? We'd like to compare whether we got the
> same issue.

I'm not sure there's any single magic commit I can point to. When I
started working on dw_mmc it was terrible at handling error cases and
would often crash / hang / stop all future communication upon certain
classes or efforts. There were dozens of problems we've had to fix
over the years. These problems showed up when we started supporting
HS200 / UHS since the tuning phase really stress the error handling of
the host controller.

I searched and by the time we were supporting Broadcom SDIO cards the
error handling was already pretty good. ...but if we hadn't already
made the error handling more robust for UHS tuning then we would have
definitely hit these types of problems. The only problem I remember
having to solve in dw_mmc that was unique to Broadcom was commit
0bdbd0e88cf6 ("mmc: dw_mmc: Don't start commands while busy"). Any
chance that could be what you're hitting?

What host controller are you having problems with?

-Doug

2019-06-04 16:52:27

by Arend Van Spriel

[permalink] [raw]
Subject: Re: [PATCH 1/3] brcmfmac: re-enable command decode in sdio_aos for BRCM 4354

On June 4, 2019 6:01:26 PM Doug Anderson <[email protected]> wrote:

> Hi,
>
> On Mon, Jun 3, 2019 at 8:20 PM Wright Feng <[email protected]> wrote:
>>
>> On 2019/5/29 上午 12:11, Arend Van Spriel wrote:
>> > On May 28, 2019 6:09:21 PM Arend Van Spriel
>> > <[email protected]> wrote:
>> >
>> >> On May 28, 2019 5:52:10 PM Doug Anderson <[email protected]> wrote:
>> >>
>> >>> Hi,
>> >>>
>> >>> On Tue, May 28, 2019 at 5:18 AM Kalle Valo <[email protected]> wrote:
>> >>>>
>> >>>> Douglas Anderson <[email protected]> wrote:
>> >>>>
>> >>>> > In commit 29f6589140a1 ("brcmfmac: disable command decode in
>> >>>> > sdio_aos") we disabled something called "command decode in sdio_aos"
>> >>>> > for a whole bunch of Broadcom SDIO WiFi parts.
>> >>>> >
>> >>>> > After that patch landed I find that my kernel log on
>> >>>> > rk3288-veyron-minnie and rk3288-veyron-speedy is filled with:
>> >>>> > brcmfmac: brcmf_sdio_bus_sleep: error while changing bus sleep
>> >>>> state -110
>> >>>> >
>> >>>> > This seems to happen every time the Broadcom WiFi transitions out of
>> >>>> > sleep mode. Reverting the part of the commit that affects the
>> >>>> WiFi on
>> >>>> > my boards fixes the problem for me, so that's what this patch does.
>> >>>> >
>> >>>> > Note that, in general, the justification in the original commit
>> >>>> seemed
>> >>>> > a little weak. It looked like someone was testing on a SD card
>> >>>> > controller that would sometimes die if there were CRC errors on the
>> >>>> > bus. This used to happen back in early days of dw_mmc (the
>> >>>> controller
>> >>>> > on my boards), but we fixed it. Disabling a feature on all boards
>> >>>> > just because one SD card controller is broken seems bad. ...so
>> >>>> > instead of just this patch possibly the right thing to do is to fully
>> >>>> > revert the original commit.
>> >>>> >
>> Since the commit 29f6589140a1 ("brcmfmac: disable command decode in
>> sdio_aos") causes the regression on other SD card controller, it is
>> better to revert it as you mentioned.
>> Actually, without the commit, we hit MMC timeout(-110) and hanged
>> instead of CRC error in our test.
>
> Any chance I can convince you to provide some official tags like
> Reviewed-by or Tested-by on the revert?
>
>> Would you please share the analysis of
>> dw_mmc issue which you fixed? We'd like to compare whether we got the
>> same issue.
>
> I'm not sure there's any single magic commit I can point to. When I
> started working on dw_mmc it was terrible at handling error cases and
> would often crash / hang / stop all future communication upon certain
> classes or efforts. There were dozens of problems we've had to fix
> over the years. These problems showed up when we started supporting
> HS200 / UHS since the tuning phase really stress the error handling of
> the host controller.
>
> I searched and by the time we were supporting Broadcom SDIO cards the
> error handling was already pretty good. ...but if we hadn't already
> made the error handling more robust for UHS tuning then we would have
> definitely hit these types of problems. The only problem I remember
> having to solve in dw_mmc that was unique to Broadcom was commit
> 0bdbd0e88cf6 ("mmc: dw_mmc: Don't start commands while busy"). Any
> chance that could be what you're hitting?

That is indeed an issue I recall resulting in -110 errors.

> What host controller are you having problems with?

Knowing that will be a good start.

Regards,
Arend