musb: communication issue with more than 12 FTDI ports

musb: communication issue with more than 12 FTDI ports

[Yegor Yefremov]

We have a problem, when using more than 12 FTDI ports. Kernels tried:
3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz

Below the USB topology:

# lsusb -t
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
    |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
        |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
            |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
            |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
            |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
            |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
            |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
            |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
            |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
            |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
            |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
        |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
        |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
        |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
        |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
        |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
        |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
        |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
        |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M

When using 12 ports and performing serial test (a pair of ports is
connected via null-modem cable and a rather short string ca. 90
characters will be sent alternating at 1200 and 115200b/s, testing
scripts are written in Python and running as own processes per a pair
of ports) there are no timeouts, i.e. all sent characters will be
received. As soon as I open ports 13 and 14 I start to get arbitrary
timeouts  (from test software point of view) on all ports.

In order to check, if ftdi_sio has primary to do with this issue, I've
performed the same test on a PC and PandaBoard Rev. A2 (EHCI port) and
there were no issues with 16 ports. So it seems to have something to
do with am335x + musb + number of end points.

Any idea? Let me know, if you need our test script.

Yegor
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Re: musb: communication issue with more than 12 FTDI ports

[Yegor Yefremov]

On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
<yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
> We have a problem, when using more than 12 FTDI ports. Kernels tried:
> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>
> Below the USB topology:
>
> # lsusb -t
> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>     |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>         |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>             |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>             |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>             |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>             |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>             |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>             |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>             |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>             |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>             |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>         |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>         |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>         |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>         |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>         |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>         |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>         |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>         |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>
> When using 12 ports and performing serial test (a pair of ports is
> connected via null-modem cable and a rather short string ca. 90
> characters will be sent alternating at 1200 and 115200b/s, testing
> scripts are written in Python and running as own processes per a pair
> of ports) there are no timeouts, i.e. all sent characters will be
> received. As soon as I open ports 13 and 14 I start to get arbitrary
> timeouts  (from test software point of view) on all ports.
>
> In order to check, if ftdi_sio has primary to do with this issue, I've
> performed the same test on a PC and PandaBoard Rev. A2 (EHCI port) and
> there were no issues with 16 ports. So it seems to have something to
> do with am335x + musb + number of end points.
>
> Any idea? Let me know, if you need our test script.

>From time to time I get following warnings (4.3.0-rc5):

musb_host_rx 1915: RX1 dma busy, csr 2020
musb_host_rx 1915: RX4 dma busy, csr 2020
musb_host_rx 1915: RX7 dma busy, csr 2220
musb_host_rx 1915: RX1 dma busy, csr 2020

Though they are not timely related to serial test timeouts.

Yegor
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RE: musb: communication issue with more than 12 FTDI ports

[Konstantin Shkolnyy]

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Some host controllers just can't support so many pipes opened at once. Check what the SoC spec says about that.

-----Original Message-----
From: linux-usb-owner@vger.kernel.org [mailto:linux-usb-owner@vger.kernel.org] On Behalf Of Yegor Yefremov
Sent: Monday, October 12, 2015 05:35
To: linux-usb
Cc: linux-omap@vger.kernel.org; Felipe Balbi
Subject: Re: musb: communication issue with more than 12 FTDI ports

On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov <yegorslists@googlemail.com> wrote:
> We have a problem, when using more than 12 FTDI ports. Kernels tried:
> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>
> Below the USB topology:
>
> # lsusb -t
> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>     |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>         |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>             |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>             |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>             |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>             |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>             |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>             |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>             |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>             |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>             |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>         |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>         |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>         |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>         |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>         |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>         |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>         |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>         |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>
> When using 12 ports and performing serial test (a pair of ports is 
> connected via null-modem cable and a rather short string ca. 90 
> characters will be sent alternating at 1200 and 115200b/s, testing 
> scripts are written in Python and running as own processes per a pair 
> of ports) there are no timeouts, i.e. all sent characters will be 
> received. As soon as I open ports 13 and 14 I start to get arbitrary 
> timeouts  (from test software point of view) on all ports.
>
> In order to check, if ftdi_sio has primary to do with this issue, I've 
> performed the same test on a PC and PandaBoard Rev. A2 (EHCI port) and 
> there were no issues with 16 ports. So it seems to have something to 
> do with am335x + musb + number of end points.
>
> Any idea? Let me know, if you need our test script.

From time to time I get following warnings (4.3.0-rc5):

musb_host_rx 1915: RX1 dma busy, csr 2020 musb_host_rx 1915: RX4 dma busy, csr 2020 musb_host_rx 1915: RX7 dma busy, csr 2220 musb_host_rx 1915: RX1 dma busy, csr 2020

Though they are not timely related to serial test timeouts.

Yegor
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Re: musb: communication issue with more than 12 FTDI ports

[Felipe Balbi]

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Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>
>> Below the USB topology:
>>
>> # lsusb -t
>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>     |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>         |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>             |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>             |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>             |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>             |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>             |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>             |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>             |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>             |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>             |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>         |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>         |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>         |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>         |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>         |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>         |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>         |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>         |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>>
>> When using 12 ports and performing serial test (a pair of ports is
>> connected via null-modem cable and a rather short string ca. 90
>> characters will be sent alternating at 1200 and 115200b/s, testing
>> scripts are written in Python and running as own processes per a pair
>> of ports) there are no timeouts, i.e. all sent characters will be
>> received. As soon as I open ports 13 and 14 I start to get arbitrary
>> timeouts  (from test software point of view) on all ports.
>>
>> In order to check, if ftdi_sio has primary to do with this issue, I've
>> performed the same test on a PC and PandaBoard Rev. A2 (EHCI port) and
>> there were no issues with 16 ports. So it seems to have something to
>> do with am335x + musb + number of end points.
>>
>> Any idea? Let me know, if you need our test script.
>
> From time to time I get following warnings (4.3.0-rc5):
>
> musb_host_rx 1915: RX1 dma busy, csr 2020
> musb_host_rx 1915: RX4 dma busy, csr 2020
> musb_host_rx 1915: RX7 dma busy, csr 2220
> musb_host_rx 1915: RX1 dma busy, csr 2020
>
> Though they are not timely related to serial test timeouts.

yeah, I don't think MUSB can easily handle that. IIRC, endpoint
scheduling in MUSB is rather bad. While we have enough endpoints to
handle this case, you might be running into some IP (or driver) issues.

Bin, have you ever tested this many serial devices on AM335x ?

-- 
balbi

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Re: musb: communication issue with more than 12 FTDI ports

[Bin Liu]

Hi,

On 10/13/2015 01:22 PM, Felipe Balbi wrote:
> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>
>>> Below the USB topology:
>>>
>>> # lsusb -t
>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>      |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>          |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>              |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>              |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>              |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>              |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>              |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>              |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>              |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>              |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>              |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>          |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>          |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>          |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>          |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>          |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>          |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>          |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>          |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M

How many EPs does each FTDI device require? at least one INT EP, right? 
If I read it right, the topology above has 2 hubs, and 16 high-speed 
FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT 
EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP 
configuration used by default. I am wondering how those devices got 
enumerated properly.

>>>
>>> When using 12 ports and performing serial test (a pair of ports is
>>> connected via null-modem cable and a rather short string ca. 90
>>> characters will be sent alternating at 1200 and 115200b/s, testing
>>> scripts are written in Python and running as own processes per a pair
>>> of ports) there are no timeouts, i.e. all sent characters will be
>>> received. As soon as I open ports 13 and 14 I start to get arbitrary
>>> timeouts  (from test software point of view) on all ports.
>>>
>>> In order to check, if ftdi_sio has primary to do with this issue, I've
>>> performed the same test on a PC and PandaBoard Rev. A2 (EHCI port) and
>>> there were no issues with 16 ports. So it seems to have something to
>>> do with am335x + musb + number of end points.
>>>
>>> Any idea? Let me know, if you need our test script.
>>
>>  From time to time I get following warnings (4.3.0-rc5):
>>
>> musb_host_rx 1915: RX1 dma busy, csr 2020
>> musb_host_rx 1915: RX4 dma busy, csr 2020
>> musb_host_rx 1915: RX7 dma busy, csr 2220
>> musb_host_rx 1915: RX1 dma busy, csr 2020
>>
>> Though they are not timely related to serial test timeouts.
>
> yeah, I don't think MUSB can easily handle that. IIRC, endpoint
> scheduling in MUSB is rather bad. While we have enough endpoints to
> handle this case, you might be running into some IP (or driver) issues.
>
> Bin, have you ever tested this many serial devices on AM335x ?

No, I never tested this many devices. It could be resource limitation, 
but the log above is about CPPI, so I recommend to test with CPPI 
disabled to isolate if this is MUSB issue or CPPI.

Regards,
-Bin.

>
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Re: musb: communication issue with more than 12 FTDI ports

[Felipe Balbi]

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Hi,

Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
> Hi,
>
> On 10/13/2015 01:22 PM, Felipe Balbi wrote:
>> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>>
>>>> Below the USB topology:
>>>>
>>>> # lsusb -t
>>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>      |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>>          |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>>              |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>>              |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>>              |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>>              |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>>              |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>>              |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>>              |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>>              |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>>              |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>>          |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>>          |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>>          |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>>          |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>>          |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>>          |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>>          |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>>          |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>
> How many EPs does each FTDI device require? at least one INT EP, right? 
> If I read it right, the topology above has 2 hubs, and 16 high-speed 
> FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT 
> EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP 
> configuration used by default. I am wondering how those devices got 
> enumerated properly.

dynamic EP allocation, but that has its own limitations.

-- 
balbi

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Re: musb: communication issue with more than 12 FTDI ports

[Bin Liu]

On 10/14/2015 10:56 AM, Felipe Balbi wrote:
>
> Hi,
>
> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>> Hi,
>>
>> On 10/13/2015 01:22 PM, Felipe Balbi wrote:
>>> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>>>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>>>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>>>
>>>>> Below the USB topology:
>>>>>
>>>>> # lsusb -t
>>>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>       |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>>>           |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>>>               |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>>>               |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>               |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>               |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>               |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>               |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>               |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>               |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>               |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>           |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>           |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>           |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>           |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>           |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>           |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>           |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>           |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>>
>> How many EPs does each FTDI device require? at least one INT EP, right?
>> If I read it right, the topology above has 2 hubs, and 16 high-speed
>> FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT
>> EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP
>> configuration used by default. I am wondering how those devices got
>> enumerated properly.
>
> dynamic EP allocation, but that has its own limitations.
>
MUSB does not support dynamic EP allocation for INT/ISOCH.
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Re: musb: communication issue with more than 12 FTDI ports

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 2900 bytes --]


Hi,

Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
> On 10/14/2015 10:56 AM, Felipe Balbi wrote:
>>
>> Hi,
>>
>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>> Hi,
>>>
>>> On 10/13/2015 01:22 PM, Felipe Balbi wrote:
>>>> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>>>>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>>>>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>>>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>>>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>>>>
>>>>>> Below the USB topology:
>>>>>>
>>>>>> # lsusb -t
>>>>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>       |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>>>>           |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>>>>               |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>>>>               |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>               |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>               |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>               |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>               |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>               |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>               |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>               |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>           |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>           |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>           |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>           |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>           |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>           |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>           |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>           |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>>>
>>> How many EPs does each FTDI device require? at least one INT EP, right?
>>> If I read it right, the topology above has 2 hubs, and 16 high-speed
>>> FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT
>>> EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP
>>> configuration used by default. I am wondering how those devices got
>>> enumerated properly.
>>
>> dynamic EP allocation, but that has its own limitations.
>>
> MUSB does not support dynamic EP allocation for INT/ISOCH.

I remember isoc doesn't, not sure about int. Do you remember where that
part of the code is off the top of your head ?

-- 
balbi

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Re: musb: communication issue with more than 12 FTDI ports

[Bin Liu]

Felipe,

On 10/14/2015 11:25 AM, Felipe Balbi wrote:
>
> Hi,
>
> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>> On 10/14/2015 10:56 AM, Felipe Balbi wrote:
>>>
>>> Hi,
>>>
>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>> Hi,
>>>>
>>>> On 10/13/2015 01:22 PM, Felipe Balbi wrote:
>>>>> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>>>>>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>>>>>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>>>>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>>>>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>>>>>
>>>>>>> Below the USB topology:
>>>>>>>
>>>>>>> # lsusb -t
>>>>>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>        |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>            |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>                |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>>>>>                |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>                |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>                |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>                |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>                |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>                |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>                |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>                |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>            |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>            |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>            |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>            |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>            |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>            |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>            |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>            |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>>>>
>>>> How many EPs does each FTDI device require? at least one INT EP, right?
>>>> If I read it right, the topology above has 2 hubs, and 16 high-speed
>>>> FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT
>>>> EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP
>>>> configuration used by default. I am wondering how those devices got
>>>> enumerated properly.
>>>
>>> dynamic EP allocation, but that has its own limitations.
>>>
>> MUSB does not support dynamic EP allocation for INT/ISOCH.
>
> I remember isoc doesn't, not sure about int. Do you remember where that
> part of the code is off the top of your head ?
>

The MUSB EP allocation is in musb_schedule() in musb_host.c.

It does not have specific policy for INT/ISOCH, but the issue is that 
for periodic EP, it got allocated during device enumeration but freed 
only when the device is disconnected. So practically there is no dynamic 
EP allocation for INT/ISOCH.

Regards,
-Bin.
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Re: musb: communication issue with more than 12 FTDI ports

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 6896 bytes --]


Hi,

Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
> Felipe,
>
> On 10/14/2015 11:25 AM, Felipe Balbi wrote:
>>
>> Hi,
>>
>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>> On 10/14/2015 10:56 AM, Felipe Balbi wrote:
>>>>
>>>> Hi,
>>>>
>>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>>> Hi,
>>>>>
>>>>> On 10/13/2015 01:22 PM, Felipe Balbi wrote:
>>>>>> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>>>>>>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>>>>>>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>>>>>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>>>>>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>>>>>>
>>>>>>>> Below the USB topology:
>>>>>>>>
>>>>>>>> # lsusb -t
>>>>>>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>>        |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>>            |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>>                |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>>>>>>                |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>                |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>                |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>                |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>                |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>                |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>                |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>                |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>            |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>            |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>            |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>            |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>            |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>            |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>            |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>            |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>
>>>>> How many EPs does each FTDI device require? at least one INT EP, right?
>>>>> If I read it right, the topology above has 2 hubs, and 16 high-speed
>>>>> FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT
>>>>> EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP
>>>>> configuration used by default. I am wondering how those devices got
>>>>> enumerated properly.
>>>>
>>>> dynamic EP allocation, but that has its own limitations.
>>>>
>>> MUSB does not support dynamic EP allocation for INT/ISOCH.
>>
>> I remember isoc doesn't, not sure about int. Do you remember where that
>> part of the code is off the top of your head ?
>>
>
> The MUSB EP allocation is in musb_schedule() in musb_host.c.
>
> It does not have specific policy for INT/ISOCH, but the issue is that 
> for periodic EP, it got allocated during device enumeration but freed 
> only when the device is disconnected. So practically there is no dynamic 
> EP allocation for INT/ISOCH.

This is not exactly what I can see when trying things out:

minicom.cap:56:[   90.909917] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:66:[   91.175860] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:100:[   91.697827] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:106:[   91.818066] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
minicom.cap:149:[   92.475792] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:162:[   92.736808] musb-hdrc musb-hdrc.1.auto: qh dc07d5c0 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:207:[   93.703046] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
minicom.cap:215:[   93.977574] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
minicom.cap:240:[   94.388472] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
minicom.cap:289:[   95.422325] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
minicom.cap:305:[   95.688207] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
minicom.cap:335:[   96.291453] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
minicom.cap:410:[   97.696976] musb-hdrc musb-hdrc.1.auto: qh df6b70c0 urb dc011f40 dev11 ep1in-intr, hw_ep 2, dd842080/8
minicom.cap:56:[   90.909917] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:66:[   91.175860] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:100:[   91.697827] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:106:[   91.818066] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
minicom.cap:149:[   92.475792] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:162:[   92.736808] musb-hdrc musb-hdrc.1.auto: qh dc07d5c0 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
minicom.cap:207:[   93.703046] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
minicom.cap:215:[   93.977574] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
minicom.cap:240:[   94.388472] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
minicom.cap:289:[   95.422325] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
minicom.cap:305:[   95.688207] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
minicom.cap:335:[   96.291453] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
minicom.cap:410:[   97.696976] musb-hdrc musb-hdrc.1.auto: qh df6b70c0 urb dc011f40 dev11 ep1in-intr, hw_ep 2, dd842080/8

Note how the same ep1in-intr was used with different devices and
different hw_eps. OTOH, within the same device, hw_ep was
constant. Hmmm...


-- 
balbi

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Re: musb: communication issue with more than 12 FTDI ports

[Bin Liu]

On 10/14/2015 12:05 PM, Felipe Balbi wrote:
>
> Hi,
>
> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>> Felipe,
>>
>> On 10/14/2015 11:25 AM, Felipe Balbi wrote:
>>>
>>> Hi,
>>>
>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>> On 10/14/2015 10:56 AM, Felipe Balbi wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>>>> Hi,
>>>>>>
>>>>>> On 10/13/2015 01:22 PM, Felipe Balbi wrote:
>>>>>>> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>>>>>>>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>>>>>>>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>>>>>>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>>>>>>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>>>>>>>
>>>>>>>>> Below the USB topology:
>>>>>>>>>
>>>>>>>>> # lsusb -t
>>>>>>>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>>>         |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>>>             |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>>>                 |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>>>>>>>                 |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>                 |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>                 |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>                 |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>                 |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>                 |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>                 |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>                 |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>             |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>             |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>             |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>             |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>             |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>             |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>             |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>             |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>
>>>>>> How many EPs does each FTDI device require? at least one INT EP, right?
>>>>>> If I read it right, the topology above has 2 hubs, and 16 high-speed
>>>>>> FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT
>>>>>> EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP
>>>>>> configuration used by default. I am wondering how those devices got
>>>>>> enumerated properly.
>>>>>
>>>>> dynamic EP allocation, but that has its own limitations.
>>>>>
>>>> MUSB does not support dynamic EP allocation for INT/ISOCH.
>>>
>>> I remember isoc doesn't, not sure about int. Do you remember where that
>>> part of the code is off the top of your head ?
>>>
>>
>> The MUSB EP allocation is in musb_schedule() in musb_host.c.
>>
>> It does not have specific policy for INT/ISOCH, but the issue is that
>> for periodic EP, it got allocated during device enumeration but freed
>> only when the device is disconnected. So practically there is no dynamic
>> EP allocation for INT/ISOCH.
>
> This is not exactly what I can see when trying things out:
>
> minicom.cap:56:[   90.909917] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:66:[   91.175860] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:100:[   91.697827] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:106:[   91.818066] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
> minicom.cap:149:[   92.475792] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:162:[   92.736808] musb-hdrc musb-hdrc.1.auto: qh dc07d5c0 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:207:[   93.703046] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
> minicom.cap:215:[   93.977574] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
> minicom.cap:240:[   94.388472] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
> minicom.cap:289:[   95.422325] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
> minicom.cap:305:[   95.688207] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
> minicom.cap:335:[   96.291453] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
> minicom.cap:410:[   97.696976] musb-hdrc musb-hdrc.1.auto: qh df6b70c0 urb dc011f40 dev11 ep1in-intr, hw_ep 2, dd842080/8
> minicom.cap:56:[   90.909917] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:66:[   91.175860] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:100:[   91.697827] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:106:[   91.818066] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
> minicom.cap:149:[   92.475792] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:162:[   92.736808] musb-hdrc musb-hdrc.1.auto: qh dc07d5c0 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
> minicom.cap:207:[   93.703046] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
> minicom.cap:215:[   93.977574] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
> minicom.cap:240:[   94.388472] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
> minicom.cap:289:[   95.422325] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
> minicom.cap:305:[   95.688207] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
> minicom.cap:335:[   96.291453] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
> minicom.cap:410:[   97.696976] musb-hdrc musb-hdrc.1.auto: qh df6b70c0 urb dc011f40 dev11 ep1in-intr, hw_ep 2, dd842080/8
>
> Note how the same ep1in-intr was used with different devices and
> different hw_eps. OTOH, within the same device, hw_ep was

Maybe I am wrong, but ep1in-intr is the EP reference to the device EP, 
while hw_ep is the reference to MUSB host EP.

> constant. Hmmm...

My understanding here is that a dedicated MUSB EP is allocated 
permanently for each device.

>
>
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Re: musb: communication issue with more than 12 FTDI ports

[Felipe Balbi]

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Hi,

Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
> On 10/14/2015 12:05 PM, Felipe Balbi wrote:
>>
>> Hi,
>>
>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>> Felipe,
>>>
>>> On 10/14/2015 11:25 AM, Felipe Balbi wrote:
>>>>
>>>> Hi,
>>>>
>>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>>> On 10/14/2015 10:56 AM, Felipe Balbi wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>>>>> Hi,
>>>>>>>
>>>>>>> On 10/13/2015 01:22 PM, Felipe Balbi wrote:
>>>>>>>> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>>>>>>>>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>>>>>>>>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>>>>>>>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>>>>>>>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>>>>>>>>
>>>>>>>>>> Below the USB topology:
>>>>>>>>>>
>>>>>>>>>> # lsusb -t
>>>>>>>>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>>>>         |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>>>>             |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>>>>                 |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>>>>>>>>                 |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>                 |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>                 |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>                 |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>                 |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>                 |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>                 |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>                 |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>             |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>             |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>             |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>             |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>             |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>             |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>             |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>             |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>
>>>>>>> How many EPs does each FTDI device require? at least one INT EP, right?
>>>>>>> If I read it right, the topology above has 2 hubs, and 16 high-speed
>>>>>>> FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT
>>>>>>> EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP
>>>>>>> configuration used by default. I am wondering how those devices got
>>>>>>> enumerated properly.
>>>>>>
>>>>>> dynamic EP allocation, but that has its own limitations.
>>>>>>
>>>>> MUSB does not support dynamic EP allocation for INT/ISOCH.
>>>>
>>>> I remember isoc doesn't, not sure about int. Do you remember where that
>>>> part of the code is off the top of your head ?
>>>>
>>>
>>> The MUSB EP allocation is in musb_schedule() in musb_host.c.
>>>
>>> It does not have specific policy for INT/ISOCH, but the issue is that
>>> for periodic EP, it got allocated during device enumeration but freed
>>> only when the device is disconnected. So practically there is no dynamic
>>> EP allocation for INT/ISOCH.
>>
>> This is not exactly what I can see when trying things out:
>>
>> minicom.cap:56:[   90.909917] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:66:[   91.175860] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:100:[   91.697827] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:106:[   91.818066] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>> minicom.cap:149:[   92.475792] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:162:[   92.736808] musb-hdrc musb-hdrc.1.auto: qh dc07d5c0 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:207:[   93.703046] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>> minicom.cap:215:[   93.977574] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>> minicom.cap:240:[   94.388472] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>> minicom.cap:289:[   95.422325] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>> minicom.cap:305:[   95.688207] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>> minicom.cap:335:[   96.291453] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>> minicom.cap:410:[   97.696976] musb-hdrc musb-hdrc.1.auto: qh df6b70c0 urb dc011f40 dev11 ep1in-intr, hw_ep 2, dd842080/8
>> minicom.cap:56:[   90.909917] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:66:[   91.175860] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:100:[   91.697827] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:106:[   91.818066] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>> minicom.cap:149:[   92.475792] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:162:[   92.736808] musb-hdrc musb-hdrc.1.auto: qh dc07d5c0 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>> minicom.cap:207:[   93.703046] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>> minicom.cap:215:[   93.977574] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>> minicom.cap:240:[   94.388472] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>> minicom.cap:289:[   95.422325] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>> minicom.cap:305:[   95.688207] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>> minicom.cap:335:[   96.291453] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>> minicom.cap:410:[   97.696976] musb-hdrc musb-hdrc.1.auto: qh df6b70c0 urb dc011f40 dev11 ep1in-intr, hw_ep 2, dd842080/8
>>
>> Note how the same ep1in-intr was used with different devices and
>> different hw_eps. OTOH, within the same device, hw_ep was
>
> Maybe I am wrong, but ep1in-intr is the EP reference to the device EP, 
> while hw_ep is the reference to MUSB host EP.

We can't really know which EP the device side is using, right ? :-) The
device sides gives us an address in the EP descriptor, but that's just a
USB view, we don't know which hw endpoint the device is using; we only
know its USB address.

>> constant. Hmmm...
>
> My understanding here is that a dedicated MUSB EP is allocated 
> permanently for each device.

Could be, it has been quite a long time since I messed around that part
of MUSB.

-- 
balbi

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Re: musb: communication issue with more than 12 FTDI ports

[Bin Liu]

On 10/14/2015 12:19 PM, Felipe Balbi wrote:
>
> Hi,
>
> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>> On 10/14/2015 12:05 PM, Felipe Balbi wrote:
>>>
>>> Hi,
>>>
>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>> Felipe,
>>>>
>>>> On 10/14/2015 11:25 AM, Felipe Balbi wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>>>> On 10/14/2015 10:56 AM, Felipe Balbi wrote:
>>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> writes:
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> On 10/13/2015 01:22 PM, Felipe Balbi wrote:
>>>>>>>>> Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> writes:
>>>>>>>>>> On Mon, Oct 12, 2015 at 11:34 AM, Yegor Yefremov
>>>>>>>>>> <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>>>>>>>>>>> We have a problem, when using more than 12 FTDI ports. Kernels tried:
>>>>>>>>>>> 3.18.1, 4.2.3 and 4.3-rc5. SoC am335x 600MHz
>>>>>>>>>>>
>>>>>>>>>>> Below the USB topology:
>>>>>>>>>>>
>>>>>>>>>>> # lsusb -t
>>>>>>>>>>> /:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>>>>> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M
>>>>>>>>>>>          |__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>>>>>              |__ Port 1: Dev 9, If 0, Class=, Driver=hub/4p, 480M
>>>>>>>>>>>                  |__ Port 1: Dev 10, If 0, Class=, Driver=ftdi_sio, 12M
>>>>>>>>>>>                  |__ Port 2: Dev 11, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>                  |__ Port 2: Dev 11, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>                  |__ Port 2: Dev 11, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>                  |__ Port 2: Dev 11, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>                  |__ Port 3: Dev 12, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>                  |__ Port 3: Dev 12, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>                  |__ Port 3: Dev 12, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>                  |__ Port 3: Dev 12, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>              |__ Port 2: Dev 4, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>              |__ Port 2: Dev 4, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>              |__ Port 2: Dev 4, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>              |__ Port 2: Dev 4, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>              |__ Port 3: Dev 7, If 0, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>              |__ Port 3: Dev 7, If 1, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>              |__ Port 3: Dev 7, If 2, Class=, Driver=ftdi_sio, 480M
>>>>>>>>>>>              |__ Port 3: Dev 7, If 3, Class=, Driver=ftdi_sio, 480M
>>>>>>>>
>>>>>>>> How many EPs does each FTDI device require? at least one INT EP, right?
>>>>>>>> If I read it right, the topology above has 2 hubs, and 16 high-speed
>>>>>>>> FTDI and 1 full-speed FTDI. So it requires at least 18 high-speed INT
>>>>>>>> EPs. MUSB driver only has 11 high-speed EPs for mode-4 which is the EP
>>>>>>>> configuration used by default. I am wondering how those devices got
>>>>>>>> enumerated properly.
>>>>>>>
>>>>>>> dynamic EP allocation, but that has its own limitations.
>>>>>>>
>>>>>> MUSB does not support dynamic EP allocation for INT/ISOCH.
>>>>>
>>>>> I remember isoc doesn't, not sure about int. Do you remember where that
>>>>> part of the code is off the top of your head ?
>>>>>
>>>>
>>>> The MUSB EP allocation is in musb_schedule() in musb_host.c.
>>>>
>>>> It does not have specific policy for INT/ISOCH, but the issue is that
>>>> for periodic EP, it got allocated during device enumeration but freed
>>>> only when the device is disconnected. So practically there is no dynamic
>>>> EP allocation for INT/ISOCH.
>>>
>>> This is not exactly what I can see when trying things out:
>>>
>>> minicom.cap:56:[   90.909917] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:66:[   91.175860] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:100:[   91.697827] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:106:[   91.818066] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>>> minicom.cap:149:[   92.475792] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:162:[   92.736808] musb-hdrc musb-hdrc.1.auto: qh dc07d5c0 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:207:[   93.703046] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>>> minicom.cap:215:[   93.977574] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>>> minicom.cap:240:[   94.388472] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>>> minicom.cap:289:[   95.422325] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>>> minicom.cap:305:[   95.688207] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>>> minicom.cap:335:[   96.291453] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>>> minicom.cap:410:[   97.696976] musb-hdrc musb-hdrc.1.auto: qh df6b70c0 urb dc011f40 dev11 ep1in-intr, hw_ep 2, dd842080/8
>>> minicom.cap:56:[   90.909917] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:66:[   91.175860] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:100:[   91.697827] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:106:[   91.818066] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>>> minicom.cap:149:[   92.475792] musb-hdrc musb-hdrc.1.auto: qh df62d240 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:162:[   92.736808] musb-hdrc musb-hdrc.1.auto: qh dc07d5c0 urb dc4ebec0 dev3 ep1in-intr, hw_ep 10, df700680/1
>>> minicom.cap:207:[   93.703046] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>>> minicom.cap:215:[   93.977574] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>>> minicom.cap:240:[   94.388472] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>>> minicom.cap:289:[   95.422325] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>>> minicom.cap:305:[   95.688207] musb-hdrc musb-hdrc.1.auto: qh dc4eb340 urb df5b7e40 dev4 ep1in-intr, hw_ep 11, df5c3400/1
>>> minicom.cap:335:[   96.291453] musb-hdrc musb-hdrc.1.auto: qh df551cc0 urb df65ee40 dev7 ep1in-intr, hw_ep 12, df6a2bc0/1
>>> minicom.cap:410:[   97.696976] musb-hdrc musb-hdrc.1.auto: qh df6b70c0 urb dc011f40 dev11 ep1in-intr, hw_ep 2, dd842080/8
>>>
>>> Note how the same ep1in-intr was used with different devices and
>>> different hw_eps. OTOH, within the same device, hw_ep was
>>
>> Maybe I am wrong, but ep1in-intr is the EP reference to the device EP,
>> while hw_ep is the reference to MUSB host EP.
>
> We can't really know which EP the device side is using, right ? :-) The

Right, ep1in-intr is the EP# from the descriptor.

> device sides gives us an address in the EP descriptor, but that's just a
> USB view, we don't know which hw endpoint the device is using; we only

The host does not have to know the hw EP on the device side.

> know its USB address.

The host know the device address and each EP reported from the 
descriptors. That is all for communication.

>
>>> constant. Hmmm...
>>
>> My understanding here is that a dedicated MUSB EP is allocated
>> permanently for each device.
>
> Could be, it has been quite a long time since I messed around that part
> of MUSB.
>
Hope you can pick it up, I have a list of issues with MUSB. I did not 
send them out just because I know you have other high priority things to 
do. ;)

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