linux-kernel - Re: 回复: [PATCH v2 1/3] dt-bindings: phy: jh7110-usb-phy: Add sys-syscon property

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240815-endless-credible-324438d164f4@spud>
Date: Thu, 15 Aug 2024 15:42:00 +0100
From: Conor Dooley <conor@...nel.org>
To: Minda Chen <minda.chen@...rfivetech.com>
Cc: Conor Dooley <conor.dooley@...rochip.com>,
	Jan Kiszka <jan.kiszka@...mens.com>, Vinod Koul <vkoul@...nel.org>,
	Kishon Vijay Abraham I <kishon@...nel.org>,
	"linux-phy@...ts.infradead.org" <linux-phy@...ts.infradead.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Dan Carpenter <dan.carpenter@...aro.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>
Subject: Re: 回复: [PATCH v2 1/3]
 dt-bindings: phy: jh7110-usb-phy: Add sys-syscon property

On Thu, Aug 15, 2024 at 10:33:55AM +0000, Minda Chen wrote:
> 
> 
> > 
> > On Tue, Aug 13, 2024 at 07:31:50AM +0200, Jan Kiszka wrote:
> > > On 12.08.24 17:55, Conor Dooley wrote:
> > > > On Mon, Aug 12, 2024 at 04:15:51PM +0200, Jan Kiszka wrote:
> > > >> From: Jan Kiszka <jan.kiszka@...mens.com>
> > > >>
> > > >> Analogously to the PCI PHY, access to sys_syscon is needed to
> > > >> connect the USB PHY to its controller.
> > > >>
> > > >> Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
> > > >> Reviewed-by: Rob Herring (Arm) <robh@...nel.org>
> > > >> ---
> > > >> CC: Rob Herring <robh@...nel.org>
> > > >> CC: Krzysztof Kozlowski <krzk+dt@...nel.org>
> > > >> CC: Conor Dooley <conor+dt@...nel.org>
> > > >> ---
> > > >>  .../bindings/phy/starfive,jh7110-usb-phy.yaml         | 11
> > +++++++++++
> > > >>  1 file changed, 11 insertions(+)
> > > >>
> > > >> diff --git
> > > >> a/Documentation/devicetree/bindings/phy/starfive,jh7110-usb-phy.yam
> > > >> l
> > > >> b/Documentation/devicetree/bindings/phy/starfive,jh7110-usb-phy.yam
> > > >> l index 269e9f9f12b6..eaf0050c6f17 100644
> > > >> ---
> > > >> a/Documentation/devicetree/bindings/phy/starfive,jh7110-usb-phy.yam
> > > >> l
> > > >> +++ b/Documentation/devicetree/bindings/phy/starfive,jh7110-usb-phy
> > > >> +++ .yaml
> > > >> @@ -19,6 +19,16 @@ properties:
> > > >>    "#phy-cells":
> > > >>      const: 0
> > > >>
> > > >> +  starfive,sys-syscon:
> > > >> +    $ref: /schemas/types.yaml#/definitions/phandle-array
> > > >> +    items:
> > > >> +      - items:
> > > >> +          - description: phandle to System Register Controller
> > sys_syscon node.
> > > >> +          - description: PHY connect offset of
> > SYS_SYSCONSAIF__SYSCFG register for USB PHY.
> > > >
> > > > Why is having a new property for this required? The devicetree only
> > > > has a single usb phy, so isn't it sufficient to look up the syscon
> > > > by compatible, rather than via phandle + offset?
> > > >
> > >
> > > I didn't design this, I just copied it from
> > > starfive,jh7110-pcie-phy.yaml. As that already exists, I'm neither
> > > sure we want to change that anymore nor deviate in the pattern here.
> > 
> > To be honest, I think some of the other users of phandle + offset on this soc were
> > just copy-pasted without thinking about whether or not they were required too.
> > This one seems like it should just be a lookup by compatible in the driver instead
> > of by phandle. As a bonus, it will work with existing devicetrees - whereas your
> > current implementation will fail to probe on systems that have the old
> > devicetree, a regression for systems running with that devicetree and
> > downstream firmware.
> > 
> > Cheers,
> > Conor.
> > 
> Hi Conor
> I know you would like to put the offset value to the code, Just set syscon in dts.
> Just like pcie-starfive.c. right?

No, not quite. That still uses a phandle lookup, I was talking about
using syscon_regmap_lookup_by_compatible().

Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)