From: Stephen Warren <swarren@wwwdotorg.org>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v3 1/1] tegra: usb: Fix device enumeration problem of USB1
Date: Wed, 20 Jun 2012 10:41:52 -0600 [thread overview]
Message-ID: <4FE1FD50.1020607@wwwdotorg.org> (raw)
In-Reply-To: <4B9C9637D5087840A465BDCB251780E9E2D6EDA3E5@HKMAIL02.nvidia.com>
On 06/20/2012 03:15 AM, Jim Lin wrote:
> A known hardware issue of USB1 port where bit 1 (connect status
> change) of PORTSC register will be set after issuing Port Reset
> (like "usb reset" in u-boot command line).
> This will be treated as an error and stops later device enumeration.
>
> Therefore we clear that bit after Port Reset in order to proceed
> later device enumeration.
>
> Signed-off-by: Jim Lin <jilin@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
But a couple of nits below,
> diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c
> +/*
> + * A known hardware issue where Connect Status Change bit of PORTSC register
> + * of USB1 controller will be set after Port Reset.
> + * We have to clear it in order for later device enumeration to proceed.
> + */
It might be worth adding a note in that comment saying that this
overrides a weak symbol in ehci-hcd.c so that people know where it's called.
> +void ehci_powerup_fixup(uint32_t *status_reg, uint32_t *reg)
> +{
> + uint32_t my_reg;
I would rename this variable just "reg"; the variable doesn't belong to
a person, and names with "my" in just make me cringe.
prev parent reply other threads:[~2012-06-20 16:41 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-20 9:15 [U-Boot] [PATCH v3 1/1] tegra: usb: Fix device enumeration problem of USB1 Jim Lin
2012-06-20 16:41 ` Stephen Warren [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4FE1FD50.1020607@wwwdotorg.org \
--to=swarren@wwwdotorg.org \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox