From: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
To: Peter Maydell <peter.maydell@linaro.org>,
Graeme Gregory <graeme@xora.org.uk>
Cc: wangyuquan1236@phytium.com.cn, quic_llindhol@quicinc.com,
chenbaozi@phytium.com.cn, qemu-arm@nongnu.org,
qemu-devel@nongnu.org
Subject: Re: [PATCH 1/1] hw/arm/sbsa-ref: use XHCI to replace EHCI
Date: Wed, 31 May 2023 18:23:54 +0200 [thread overview]
Message-ID: <22b7f290-6372-4525-926e-463ab9337f29@linaro.org> (raw)
In-Reply-To: <CAFEAcA8h9-YWUYsvuERttmsEK3xi+K+xasFdoWmnFm26S6npNw@mail.gmail.com>
W dniu 31.05.2023 o 17:27, Peter Maydell pisze:
> On Wed, 31 May 2023 at 15:58, Graeme Gregory <graeme@xora.org.uk> wrote:
>> On Wed, May 31, 2023 at 03:02:29PM +0800, wangyuquan1236@phytium.com.cn wrote:
>>> From: Yuquan Wang <wangyuquan1236@phytium.com.cn>
>>>
>>> The current sbsa-ref cannot use EHCI controller which is only
>>> able to do 32-bit DMA, since sbsa-ref doesn't have RAM above 4GB.
>>> Hence, this uses XHCI to provide a usb controller with 64-bit
>>> DMA capablity instead of EHCI.
>> Should this be below 4G?
> It would be pretty disruptive to try to rearrange the memory
> map to put RAM below 4GB at this point, though in theory it's
> possible I guess. (I have a vague recollection that there was
> some reason the RAM was all put above 4GB, but can't find
> anything about that in my email archives. Perhaps Leif remembers?)
I thought that memory starts at 40bit was to not use Cortex-A53 cpu with
sbsa-ref. Nowadays it also removed Cortex-A76.
> Looking back at the archives, it seems we discussed XHCI vs
> EHCI when the sbsa-ref board went in, and the conclusion was
> that XHCI would be better. But there wasn't a sysbus XHCI device
> at that point, so we ended up committing the sbsa-ref board
> with EHCI and a plan to switch to XHCI when the sysbus-xhci
> device was done, which we then forgot about:
> https://mail.gnu.org/archive/html/qemu-arm/2018-11/msg00638.html
Moving from EHCI to XHCI on sysbus requires also firmware changes.
Or we can just add "qemu-xhci" pcie card and have USB running.
next prev parent reply other threads:[~2023-05-31 16:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-31 7:02 [PATCH 0/1] hw/arm/sbsa-ref: use XHCI to replace EHCI wangyuquan1236
2023-05-31 7:02 ` [PATCH 1/1] " wangyuquan1236
2023-05-31 14:58 ` Graeme Gregory
2023-05-31 15:27 ` Peter Maydell
2023-05-31 16:23 ` Marcin Juszkiewicz [this message]
2023-05-31 16:36 ` Leif Lindholm
2023-05-31 17:12 ` Graeme Gregory
2023-06-01 2:37 ` Chen Baozi
2023-06-01 15:01 ` Peter Maydell
2023-06-01 15:30 ` Marcin Juszkiewicz
2023-06-01 16:39 ` Peter Maydell
2023-06-01 17:11 ` Marcin Juszkiewicz
2023-06-01 17:59 ` Leif Lindholm
2023-06-01 18:07 ` Ard Biesheuvel
2023-06-02 3:24 ` Yuquan Wang
2023-06-02 9:29 ` Leif Lindholm
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