From: <Claudiu.Beznea@microchip.com>
To: <stern@rowland.harvard.edu>
Cc: alexandre.belloni@bootlin.com, gregkh@linuxfoundation.org,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Ludovic.Desroches@microchip.com,
linux-arm-kernel@lists.infradead.org,
Cristian.Birsan@microchip.com
Subject: Re: [PATCH] usb: host: ohci-at91: suspend/resume ports after/before OHCI accesses
Date: Thu, 1 Jul 2021 05:45:50 +0000 [thread overview]
Message-ID: <6a33e55d-b101-cda2-7f53-ce6e5e6ace93@microchip.com> (raw)
In-Reply-To: <20210630182137.GA743974@rowland.harvard.edu>
On 30.06.2021 21:21, Alan Stern wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> On Wed, Jun 30, 2021 at 02:46:47PM +0000, Claudiu.Beznea@microchip.com wrote:
>> On 24.06.2021 16:23, Alan Stern wrote:
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>
>>> On Thu, Jun 24, 2021 at 06:40:25AM +0000, Claudiu.Beznea@microchip.com wrote:
>>>> On 23.06.2021 19:41, Alan Stern wrote:
>>>>> Are there any systems beside the SAMA7G5 and others you tested which
>>>>> might be affected by this patch? Do they all work pretty much the
>>>>> same way? (I want to make sure no others will be adversely affected
>>>>> by this change.)
>>>>
>>>> I tested it on SAMA7G5, SAMA5D2 and SAM9X60. I tested the suspend/resume
>>>> to/from mem. On SAMA5D2 and SAM9X60 there is no clock provided by
>>>> transceiver A to OHCI. I encountered no issues on tested systems. These IPs
>>>> are also present on SAMA5D3 and SAMA5D4 systems which I haven't tested as I
>>>> expect to behave as SAMA5D2 (as the clocking scheme is the same with
>>>> SAMA5D2). I can also try it on a SAMA5D3 (I don't have a SAMA5D4 with me at
>>>> the moment), tough, just to be sure nothing is broken there too.
>>>
>>> That doesn't answer my question. I asked if there were any systems
>>> which might be affected by your patch, and you listed a bunch of
>>> systems that _aren't_ affected (that is, they continue to work
>>> properly).
>>
>> I wrongly understood the initial question.
>>
>>>
>>> What systems might run into trouble with this patch?
>>
>> These are all I haven't tested and might be affected:
>> AT91RM9200,
>> SAM9260,
>> SAM9261,
>> SAM9263,
>> SAM9N12,
>> SAM9X35,
>> SAM9G45.
>>
>> The last two (SAM9X35 and SAM9G45) have the same clocking scheme with
>> SAMA5D2 (which I tested). For the rest of them I cannot find the clocking
>> scheme in datasheet and don't have them to test (at least at the moment).
>
> I see. That seems reasonable; the others are probably the same as the
> ones you tested.
>
> Did you ever answer the question that Nicolas raised back on June 9 in:
>
> https://marc.info/?l=linux-usb&m=162324242003349&w=2
Not directly. I replied previously in this thread "For run-time control
(via ohci_at91_hub_control()), I agree with you that
the current implemented approach is not healthy (taking into account the
clock scheme above) and the fact that we do force the ports suspend on
ohci_at91_hub_control()". Nicolas was referring to ohci_at91_port_suspend()
calls in ohci_at91_hub_control() so I agreed with him that work might need
to be done also for this function.
Thank you,
Claudiu Beznea
>
> Alan Stern
>
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next prev parent reply other threads:[~2021-07-01 5:47 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-09 12:10 [PATCH] usb: host: ohci-at91: suspend/resume ports after/before OHCI accesses Claudiu Beznea
2021-06-09 12:40 ` Nicolas Ferre
2021-06-09 23:07 ` Alan Stern
2021-06-23 12:47 ` Claudiu.Beznea
2021-06-23 13:59 ` Alan Stern
2021-06-23 14:09 ` Claudiu.Beznea
2021-06-23 14:19 ` Alan Stern
2021-06-23 14:33 ` Claudiu.Beznea
2021-06-23 16:41 ` Alan Stern
2021-06-24 6:40 ` Claudiu.Beznea
2021-06-24 6:54 ` Claudiu.Beznea
2021-06-24 13:23 ` Alan Stern
2021-06-30 14:46 ` Claudiu.Beznea
2021-06-30 18:21 ` Alan Stern
2021-07-01 5:45 ` Claudiu.Beznea [this message]
2021-07-01 14:01 ` Alan Stern
2021-06-30 14:47 ` Claudiu.Beznea
2021-07-21 8:08 ` Greg KH
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