From: Johan Hovold <johan@kernel.org>
To: Michael Hanselmann <public@hansmi.ch>
Cc: linux-usb@vger.kernel.org, Johan Hovold <johan@kernel.org>,
Michael Dreher <michael@5dot1.de>,
Jonathan Olds <jontio@i4free.co.nz>
Subject: Re: [PATCH 3/4] ch341: Limit prescaler on HL340 variant
Date: Tue, 24 Mar 2020 11:41:31 +0100 [thread overview]
Message-ID: <20200324104131.GG5810@localhost> (raw)
In-Reply-To: <d76985a6dcf1b4aeec783dd8c8b59f054b51e07d.1583520568.git.public@hansmi.ch>
On Fri, Mar 06, 2020 at 07:00:44PM +0000, Michael Hanselmann wrote:
> HL340 devices, a subset of all CH340 devices, do not work correctly when
> the highest prescaler bit (0b100) is set. Limit these to the lower
> prescaler values at the cost of timing precision.
When we discussed this off list, you said that your device could handle
the highest prescaler bit being set for some rates. You specifically
confirmed that the 576000 and 921600 rates worked, while 110, 134 and
200 did not.
Could you reconfirm which, if any, of the following rates work with the
current driver?
1152000
921600
576000
200
134
110
Perhaps we can still continue supporting the higher rates, which are way
off unless using the factor-2 prescaler.
Johan
next prev parent reply other threads:[~2020-03-24 10:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-06 19:00 [PATCH 0/4] ch341: Add support for HL340 devices Michael Hanselmann
2020-03-06 19:00 ` [PATCH 1/4] ch341: Name more registers Michael Hanselmann
2020-03-24 10:20 ` Johan Hovold
2020-03-31 23:34 ` Michael Hanselmann
2020-03-06 19:00 ` [PATCH 2/4] ch341: Detect HL340 variant Michael Hanselmann
2020-03-24 10:31 ` Johan Hovold
2020-03-31 23:35 ` Michael Hanselmann
2020-03-06 19:00 ` [PATCH 3/4] ch341: Limit prescaler on " Michael Hanselmann
2020-03-24 10:41 ` Johan Hovold [this message]
2020-03-31 23:35 ` Michael Hanselmann
2020-03-06 19:00 ` [PATCH 4/4] ch341: Simulate break condition " Michael Hanselmann
2020-03-24 10:55 ` Johan Hovold
2020-03-24 10:05 ` [PATCH 0/4] ch341: Add support for HL340 devices Johan Hovold
2020-03-31 23:35 ` Michael Hanselmann
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