Re: [PATCH v1 0/2] usb: dwc2: gadget: Fixes for LPM

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Simon,


Am 07.05.2018 um 14:48 schrieb Simon Shields:
Hi Grigor,

On Wed, May 02, 2018 at 10:12:27AM +0000, Grigor Tovmasyan wrote:
Hi Simon,

On 4/21/2018 4:52 PM, Simon Shields wrote:
Hi Grigor,

On Fri, Apr 20, 2018 at 01:00:16PM +0000, Grigor Tovmasyan wrote:
Hi Simon,

On 4/19/2018 8:31 PM, Simon Shields wrote:
Hi all,

On 10/04/2018 10:21 PM, Grigor Tovmasyan wrote:
Here are two little fixes for LPM feature.

First one is coverity warning fix.

The Second one was asserted by Stefan Wahren.

Changes from version 0:

1/2:
       - Instead of converting parameter in the CHECK_RANGE macro
         to int, changed hird_threshold type from u8 to int.


Grigor Tovmasyan (2):
      usb: dwc2: gadget: Fix coverity issue
      usb: dwc2: gadget: Change LPM default values

     drivers/usb/dwc2/core.h   | 2 +-
     drivers/usb/dwc2/params.c | 8 ++++----
     2 files changed, 5 insertions(+), 5 deletions(-)
The second patch in this series fixes a regression in 4.17-rc1 using dwc2 in gadget
mode on Exynos4412, introduced by commit 7455f8b7f0b3 ("usb: dwc2: Enable
LPM"). The regression is that using the cdc_acm serial gadget (and
presumably other gadgets) serial console output will only sporadically
show up on the host (it seems to only show up as input is sent).

The second patch is not fix for described by you issue. We will try to
reproduce your issue and provide fix. Could you provide some logs or usb
traces for issue?
Here's a log[0]. The log is pretty big: I generated it with both regular and verbose
debugging enabled for DWC2. However, I suspect the relevant line is
probably:

[   95.222330] dwc2 12480000.hsotg: dwc2_hsotg_ep_queue: submit request only in active state

Which occurs whenever the controller is in LPM mode. I guess that input
makes it "work" because it reawakens the controller -- but I'm just
spitballing :-). Let me know if you need any more information from my
side.

[0]: https://urldefense.proofpoint.com/v2/url?u=https-3A__forkwhiletrue.me_-7Esimon_midas-5Fdwc2-5Flpm-5Fverbose.log&d=DwIBAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=K1ULVL1slpLXpMJJlAXSOxws4tRq0IkTBqxDkyW2hUQ&m=fkdnWR9_dgHLGH5-mN9lDclJ58GWR__m7hS3zz3am28&s=aind-wCFaB40EyTcHvphrqt6SngQTnf3CYXJxOfBjWc&e=

However, I'm unsure if completely disabling LPM is the correct fix, as the dwc2
revision in Exynos4412 (0x4f54281a) should support LPM according to the
source
Yes, we can enable LPM based on hardware configuration.

I'm not really sure how to debug this any further (vendor kernel
releases contain no mention of LPM in the gadget drivers), so any pointers
in that direction would be much appreciated.

Cheers,
Simon

Cheers,
Simon

Could you please revert "usb: dwc2: Add core state checking" patch and
try again.
This doesn't really fix the issue, but it does change the results. Now, input works
as expected, but output is still only shown after input is given (e.g.
the output of "dmesg" only shows if I press a key after executing dmesg).
However, after a few seconds the USB serial device disappears from the
host entirely. Once this has happened, reading the "regdump" of dwc2's debugfs
appears to hang the system (i.e. it no longer responds to UART). I've attached
another log[0].

the regdump is broken. Please try my patch [1]

Stefan

[1] - https://patchwork.kernel.org/patch/10381277/
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux SoC Development]     [Linux Rockchip Development]     [Linux USB Development]     [Video for Linux]     [Linux Audio Users]     [Linux SCSI]     [Yosemite News]

  Powered by Linux