From: Stephen Warren <swarren@wwwdotorg.org>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 5/7] usb: Assure Get Descriptor request is in separate microframe
Date: Wed, 4 May 2016 11:10:10 -0600 [thread overview]
Message-ID: <572A2CF2.4020505@wwwdotorg.org> (raw)
In-Reply-To: <1462308680-9366-5-git-send-email-marex@denx.de>
On 05/03/2016 02:51 PM, Marek Vasut wrote:
> The Kingston DT Ultimate USB 3.0 stick is sensitive to this first
> Get Descriptor request and if the request is not in a separate
> microframe, the stick refuses to operate. Add slight delay, which
> is enough for one microframe to pass on any USB spec revision.
> diff --git a/common/usb.c b/common/usb.c
> + /*
> + * Kingston DT Ultimate 32GB USB 3.0 seems to be extremely sensitive
> + * about this first Get Descriptor request. If there are any other
> + * requests in the first microframe, the stick crashes. Wait about
> + * one microframe duration here (1mS for USB 1.x , 125uS for USB 2.0).
> + */
> + mdelay(1);
Do we know the connection speed here? If so, we could sleep 1ms for
USB1.x and 125us for USB2.x, thus reducing any performance impact.
Still, this is a short delay that I think only happens once per actual
device so perhaps it isn't worth it.
next prev parent reply other threads:[~2016-05-04 17:10 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-03 20:51 [U-Boot] [PATCH 1/7] usb: Don't init pointer to zero, but NULL Marek Vasut
2016-05-03 20:51 ` [U-Boot] [PATCH 2/7] usb: dwc2: Resend setup packet in all fail cases Marek Vasut
2016-05-04 9:36 ` Chin Liang See
2016-05-03 20:51 ` [U-Boot] [PATCH 3/7] usb: dwc2: Throttle the setup packet resending Marek Vasut
2016-05-04 9:37 ` Chin Liang See
2016-05-04 17:08 ` Stephen Warren
2016-05-04 21:21 ` Marek Vasut
2016-05-06 18:04 ` Marek Vasut
2016-05-03 20:51 ` [U-Boot] [PATCH 4/7] usb: Wait after sending Set Configuration request Marek Vasut
2016-05-04 7:41 ` Stefan Roese
2016-05-04 9:45 ` Chin Liang See
2016-05-04 10:00 ` Stefan Roese
2016-05-04 10:24 ` Chin Liang See
2016-05-05 4:14 ` Sriram Dash
2016-05-04 10:21 ` Marek Vasut
2016-05-03 20:51 ` [U-Boot] [PATCH 5/7] usb: Assure Get Descriptor request is in separate microframe Marek Vasut
2016-05-04 8:03 ` Stefan Roese
2016-05-04 10:25 ` Marek Vasut
2016-05-04 17:10 ` Stephen Warren [this message]
2016-05-03 20:51 ` [U-Boot] [PATCH 6/7] usb: hub: Don't continue on get_port_status failure Marek Vasut
2016-05-04 8:05 ` Stefan Roese
2016-05-04 9:38 ` Chin Liang See
2016-05-03 20:51 ` [U-Boot] [PATCH 7/7] usb: hub: Increase the query delay Marek Vasut
2016-05-04 8:07 ` Stefan Roese
2016-05-04 11:39 ` Marek Vasut
2016-05-04 16:27 ` Stefan Roese
2016-05-04 17:11 ` Stephen Warren
2016-05-04 21:32 ` [U-Boot] [PATCH] " Marek Vasut
2016-05-04 21:34 ` Stephen Warren
2016-05-04 21:38 ` Marek Vasut
2016-05-04 7:36 ` [U-Boot] [PATCH 1/7] usb: Don't init pointer to zero, but NULL Stefan Roese
2016-05-04 9:35 ` Chin Liang See
2016-05-06 16:36 ` Marek Vasut
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