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From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
	DRI mailing list <dri-devel@lists.freedesktop.org>,
	The etnaviv authors <etnaviv@lists.freedesktop.org>,
	Lubomir Rintel <lkundrak@v3.sk>
Subject: Re: [PATCH 2/3] drm/etnaviv: Don't ignore errors on getting clocks
Date: Thu, 14 May 2020 09:27:56 +0100	[thread overview]
Message-ID: <20200514082755.GN1551@shell.armlinux.org.uk> (raw)
In-Reply-To: <1e15be39906034a95b86c026e060ed9866586d94.camel@pengutronix.de>

On Thu, May 14, 2020 at 10:18:02AM +0200, Lucas Stach wrote:
> Am Mittwoch, den 13.05.2020, 23:41 -0300 schrieb Fabio Estevam:
> > On Wed, May 13, 2020 at 2:09 PM Fabio Estevam <festevam@gmail.com> wrote:
> > 
> > > The binding doc Documentation/devicetree/bindings/gpu/vivante,gc.yaml
> > > says that only the 'reg' clock could be optional, the others are
> > > required.
> > 
> > arch/arm/boot/dts/dove.dtsi only uses the 'core' clock.
> > arch/arm/boot/dts/stm32mp157.dtsi uses 'bus' and 'core'
> > 
> > Maybe the binding needs to be updated and it seems that using
> > devm_clk_get_optional() like you propose is safe.
> 
> The binding is correct as-is. We want to require those clocks to be
> present, but the dove DT was added before the binding was finalized, so
> the driver still treats the clocks as optional to not break
> compatibility with old DTs. Maybe this warrants a comment in the
> code...

The binding doc in mainline says:

  clocks:
    items:
      - description: AXI/master interface clock
      - description: GPU core clock
      - description: Shader clock (only required if GPU has feature PIPE_3D)
      - description: AHB/slave interface clock (only required if GPU can gate slave interface independently)
    minItems: 1
    maxItems: 4

  clock-names:
    items:
      enum: [ bus, core, shader, reg ]
    minItems: 1
    maxItems: 4

which looks correct to me - and means that Dove is compliant with that.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 10.2Mbps down 587kbps up
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WARNING: multiple messages have this Message-ID (diff)
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>,
	Lubomir Rintel <lkundrak@v3.sk>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	DRI mailing list <dri-devel@lists.freedesktop.org>,
	The etnaviv authors <etnaviv@lists.freedesktop.org>,
	Christian Gmeiner <christian.gmeiner@gmail.com>
Subject: Re: [PATCH 2/3] drm/etnaviv: Don't ignore errors on getting clocks
Date: Thu, 14 May 2020 09:27:56 +0100	[thread overview]
Message-ID: <20200514082755.GN1551@shell.armlinux.org.uk> (raw)
In-Reply-To: <1e15be39906034a95b86c026e060ed9866586d94.camel@pengutronix.de>

On Thu, May 14, 2020 at 10:18:02AM +0200, Lucas Stach wrote:
> Am Mittwoch, den 13.05.2020, 23:41 -0300 schrieb Fabio Estevam:
> > On Wed, May 13, 2020 at 2:09 PM Fabio Estevam <festevam@gmail.com> wrote:
> > 
> > > The binding doc Documentation/devicetree/bindings/gpu/vivante,gc.yaml
> > > says that only the 'reg' clock could be optional, the others are
> > > required.
> > 
> > arch/arm/boot/dts/dove.dtsi only uses the 'core' clock.
> > arch/arm/boot/dts/stm32mp157.dtsi uses 'bus' and 'core'
> > 
> > Maybe the binding needs to be updated and it seems that using
> > devm_clk_get_optional() like you propose is safe.
> 
> The binding is correct as-is. We want to require those clocks to be
> present, but the dove DT was added before the binding was finalized, so
> the driver still treats the clocks as optional to not break
> compatibility with old DTs. Maybe this warrants a comment in the
> code...

The binding doc in mainline says:

  clocks:
    items:
      - description: AXI/master interface clock
      - description: GPU core clock
      - description: Shader clock (only required if GPU has feature PIPE_3D)
      - description: AHB/slave interface clock (only required if GPU can gate slave interface independently)
    minItems: 1
    maxItems: 4

  clock-names:
    items:
      enum: [ bus, core, shader, reg ]
    minItems: 1
    maxItems: 4

which looks correct to me - and means that Dove is compliant with that.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 10.2Mbps down 587kbps up

  reply	other threads:[~2020-05-14  8:41 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <[PATCH 0/3] drm/etnaviv: Clock fixes>
2020-05-13 15:00 ` Lubomir Rintel
2020-05-13 15:00   ` [PATCH 1/3] drm/etnaviv: Fix error path on failure to enable bus clk Lubomir Rintel
2020-05-13 15:00     ` Lubomir Rintel
2020-05-13 15:00   ` [PATCH 2/3] drm/etnaviv: Don't ignore errors on getting clocks Lubomir Rintel
2020-05-13 15:00     ` Lubomir Rintel
2020-05-13 16:07     ` Fabio Estevam
2020-05-13 16:07       ` Fabio Estevam
2020-05-13 17:09     ` Fabio Estevam
2020-05-13 17:09       ` Fabio Estevam
2020-05-14  2:41       ` Fabio Estevam
2020-05-14  2:41         ` Fabio Estevam
2020-05-14  8:18         ` Lucas Stach
2020-05-14  8:18           ` Lucas Stach
2020-05-14  8:27           ` Russell King - ARM Linux admin [this message]
2020-05-14  8:27             ` Russell King - ARM Linux admin
2020-05-14  8:40             ` Lucas Stach
2020-05-14  8:40               ` Lucas Stach
2020-05-14  8:53               ` Russell King - ARM Linux admin
2020-05-14  8:53                 ` Russell King - ARM Linux admin
2020-05-20 13:38                 ` Lubomir Rintel
2020-05-20 13:38                   ` Lubomir Rintel
2020-05-20 14:04                   ` Lucas Stach
2020-05-20 14:04                     ` Lucas Stach
2020-05-20 15:00                     ` Russell King - ARM Linux admin
2020-05-20 15:00                       ` Russell King - ARM Linux admin
2020-05-23 10:22                     ` Lubomir Rintel
2020-05-23 10:22                       ` Lubomir Rintel
2020-05-13 15:00   ` [PATCH 3/3] drm/etnaviv: Simplify clock enable/disable Lubomir Rintel
2020-05-13 15:00     ` Lubomir Rintel

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