Re: [Qemu-devel] [Qemu-ppc] [PATCH-for-4.2 2/3] hw/usb/Kconfig: Add CONFIG_USB_EHCI_PCI

From: Thomas Huth <thuth@redhat.com>
To: BALATON Zoltan <balaton@eik.bme.hu>
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Alistair Francis" <Alistair.Francis@wdc.com>,
	qemu-riscv@nongnu.org, "Eduardo Habkost" <ehabkost@redhat.com>,
	"Sagar Karandikar" <sagark@eecs.berkeley.edu>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Bastian Koppelmann" <kbastian@mail.uni-paderborn.de>,
	"Helge Deller" <deller@gmx.de>,
	"Palmer Dabbelt" <palmer@sifive.com>,
	qemu-devel@nongnu.org, qemu-arm@nongnu.org, qemu-ppc@nongnu.org,
	"Gerd Hoffmann" <kraxel@redhat.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"David Gibson" <david@gibson.dropbear.id.au>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>,
	"Artyom Tarasenko" <atar4qemu@gmail.com>,
	"Richard Henderson" <rth@twiddle.net>
Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH-for-4.2 2/3] hw/usb/Kconfig: Add CONFIG_USB_EHCI_PCI
Date: Mon, 15 Jul 2019 13:19:30 +0200	[thread overview]
Message-ID: <49ee5af3-c435-a6ac-7818-e380b44c6f67@redhat.com> (raw)
In-Reply-To: <alpine.BSF.2.21.9999.1907151309190.6546@zero.eik.bme.hu>

On 15/07/2019 13.10, BALATON Zoltan wrote:
> On Mon, 15 Jul 2019, Thomas Huth wrote:
>> On 15/07/2019 12.54, BALATON Zoltan wrote:
>>> On Mon, 15 Jul 2019, Philippe Mathieu-Daudé wrote:
>>>> The USB_EHCI entry currently include PCI code. Since the EHCI
>>>> implementation is already split in sysbus/PCI, add a new
>>>> USB_EHCI_PCI. There are no logical changes, but the Kconfig
>>>> dependencies tree is cleaner.
>>>>
>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>>> ---
>>>> hw/usb/Kconfig?????? | 9 ++++++---
>>>> hw/usb/Makefile.objs | 5 +++--
>>>> 2 files changed, 9 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/hw/usb/Kconfig b/hw/usb/Kconfig
>>>> index 564305e283..495c6f2d48 100644
>>>> --- a/hw/usb/Kconfig
>>>> +++ b/hw/usb/Kconfig
>>>> @@ -19,13 +19,16 @@ config USB_OHCI_PCI
>>>>
>>>> config USB_EHCI
>>>> ??? bool
>>>> -??? default y if PCI_DEVICES
>>>> -??? depends on PCI
>>>> ??? select USB
>>>>
>>>> +config USB_EHCI_PCI
>>>> +??? bool
>>>> +??? default y if PCI_DEVICES
>>>> +??? select USB_EHCI
>>>> +
>>>> config USB_EHCI_SYSBUS
>>>> ??? bool
>>>> -??? select USB
>>>> +??? select USB_EHCI
>>>
>>> Isn't this making USB_EHCI effectively the same as USB so maybe you
>>> don't need to keep that around any more. Can you just add select USB to
>>> USB_EHCI_PCI and USB_EHCI_SYSBUS and delete USB_EHCI?
>>
>> If you want to compile without USB_EHCI_PCI and without USB_EHCI_SYSBUS,
>> but with USB (e.g. due to XHCI), I think we should not include
>> hcd-ehci.o file in the build. So I think it's fine that we have a
>> separate config switch for this file.
> 
> So shouldn't build depend on either USB_EHCI_PCI or USB_EHCI_SYSBUS
> selected then?

Boards that have a hard-wired sysbus EHCI device already select it, e.g.
EXYNOS4 in hw/arm/Kconfig. EHCI on a PCI card is optional, so it is only
marked with "default y if PCI_DEVICES" - which you can override in your
config if you don't need it.

 Thomas