All of lore.kernel.org
 help / color / mirror / Atom feed
From: Samuel Holland <samuel@sholland.org>
To: u-boot@lists.denx.de
Subject: [PATCH 4/6] usb: xhci-pci: Move reset logic out of XHCI core
Date: Mon, 8 Feb 2021 20:27:23 -0600	[thread overview]
Message-ID: <6c26292d-5b6e-6d0d-735a-26db47219680@sholland.org> (raw)
In-Reply-To: <5b4c87ea-7267-f7e5-0e35-8792f70a64f0@denx.de>

On 2/8/21 5:43 AM, Marek Vasut wrote:
> On 2/8/21 6:57 AM, Samuel Holland wrote:
>> Resetting an XHCI controller inside xhci_register undoes any register
>> setup performed by the platform driver. And at least on the Allwinner
>> H6, resetting the XHCI controller also resets the PHY, which prevents
>> the controller from working. That means the controller must be taken out
>> of reset before initializing the PHY, which must be done before calling
>> xhci_register.
>>
>> The logic in the XHCI core was added to support the Raspberry Pi 4
>> (although this was not mentioned in the commit log!), which uses the
>> xhci-pci platform driver. Move the reset logic to the platform driver,
>> where it belongs, and where it cannot interfere with other platform
>> drivers.
> 
> Are there any other XHCI drivers using the XHCI core code which might
> stop resetting correctly due to this patch ?

Since commit 0b80371b350e was merged, the only new call to xhci_register
is in USB_MTU3. Neither the binding for "mediatek,mtu3" nor any device
tree node containing that compatible string has a "resets" property. And
there have been no calls to reset_(de)assert since then, either. So I do
not see any other drivers that would be likely to break.

Samuel

  parent reply	other threads:[~2021-02-09  2:27 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-08  5:57 [PATCH 0/6] Allwinner H6 USB3 support Samuel Holland
2021-02-08  5:57 ` [PATCH 1/6] clk: sunxi: Add a dummy clock driver for the RTC Samuel Holland
2021-03-28 22:51   ` Andre Przywara
2021-02-08  5:57 ` [PATCH 2/6] clk: sunxi: h6: Add XHCI clocks Samuel Holland
2021-02-09  1:33   ` Andre Przywara
2021-02-08  5:57 ` [PATCH 3/6] phy: sun50i-usb3: Add a driver for the H6 USB3 PHY Samuel Holland
2021-02-09  1:33   ` Andre Przywara
2021-02-08  5:57 ` [PATCH 4/6] usb: xhci-pci: Move reset logic out of XHCI core Samuel Holland
2021-02-08 11:43   ` Marek Vasut
2021-02-09  1:42     ` Andre Przywara
2021-02-09  2:27     ` Samuel Holland [this message]
2021-02-09  2:28       ` Samuel Holland
2021-02-09  9:45         ` Marek Vasut
2021-02-08  5:57 ` [PATCH 5/6] usb: xhci-dwc3: Add support for clocks/resets Samuel Holland
2021-02-09  1:42   ` Andre Przywara
2021-02-09  3:01     ` Samuel Holland
2021-02-08  5:57 ` [PATCH 6/6] configs: Enable USB3 on Allwinner H6 boards Samuel Holland
2021-02-09  1:42   ` Andre Przywara
2021-02-09  1:42 ` [PATCH 0/6] Allwinner H6 USB3 support Andre Przywara
2021-02-09 10:46 ` Andre Heider
2021-04-17 14:17   ` Samuel Holland

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=6c26292d-5b6e-6d0d-735a-26db47219680@sholland.org \
    --to=samuel@sholland.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.