From: Enric Balletbo Serra <eballetbo@gmail.com>
To: Adrian Ratiu <adrian.ratiu@collabora.com>
Cc: Linux ARM <linux-arm-kernel@lists.infradead.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"open list:ARM/Rockchip SoC..."
<linux-rockchip@lists.infradead.org>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Adrian Pop <pop.adrian61@gmail.com>,
Jonas Karlman <jonas@kwiboo.se>,
linux-kernel <linux-kernel@vger.kernel.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
Andrzej Hajda <a.hajda@samsung.com>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Collabora Kernel ML <kernel@collabora.com>,
Ezequiel Garcia <ezequiel@collabora.com>,
linux-stm32@st-md-mailman.stormreply.com,
Arnaud Ferraris <arnaud.ferraris@collabora.com>,
linux-imx@nxp.com
Subject: Re: [PATCH v6 1/8] drm: bridge: dw_mipi_dsi: add initial regmap infrastructure
Date: Thu, 16 Apr 2020 22:15:19 +0200 [thread overview]
Message-ID: <CAFqH_513KB+En_xbpXSBG6Q38kYxWCgw0KO3NVxCb6fqHDaKBA@mail.gmail.com> (raw)
In-Reply-To: <87lfmvjmt5.fsf@collabora.com>
Hi Adrian,
[snip]
> >>
> >> +static void dw_mipi_dsi_get_hw_version(struct dw_mipi_dsi
> >> *dsi) +{ + regmap_read(dsi->regs, DSI_VERSION,
> >> &dsi->hw_version); + dsi->hw_version &= VERSION; +
> >> if (!dsi->hw_version) + dev_err(dsi->dev, "Failed
> >> to read DSI hw version register\n");
> >
> > Is this an error that should be ignored? If you can't get the HW
> > version, probably, there is something wrong with your hardware
> > so, don't you need to return an error?
> >
>
> After thinking a bit more about it, that error should be a
> warning.
>
> I added it because in some cases (for eg. if the peripheral clock
> is disabled) the reads can return 0 which is obviously an invalid
> version and the bridge will error in the next step when not
> finding a layout.
>
If you'll error anyway, why wait? IIUC at this point the clock *must*
be enabled, and if not, something is wrong with the driver, I don't
see any advantage on delay the error. do you have a use case where
this is called and peripheral clock disabled?
> So I'll make this a warning in v7 and explicitely mention that
> reads version == 0 can be caused by a disabled pclk.
>
-- Enric
WARNING: multiple messages have this Message-ID (diff)
From: Enric Balletbo Serra <eballetbo@gmail.com>
To: Adrian Ratiu <adrian.ratiu@collabora.com>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Adrian Pop <pop.adrian61@gmail.com>,
Jonas Karlman <jonas@kwiboo.se>,
linux-kernel <linux-kernel@vger.kernel.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
Andrzej Hajda <a.hajda@samsung.com>,
"open list:ARM/Rockchip SoC..."
<linux-rockchip@lists.infradead.org>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Arnaud Ferraris <arnaud.ferraris@collabora.com>,
Collabora Kernel ML <kernel@collabora.com>,
Ezequiel Garcia <ezequiel@collabora.com>,
linux-stm32@st-md-mailman.stormreply.com,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-imx@nxp.com
Subject: Re: [PATCH v6 1/8] drm: bridge: dw_mipi_dsi: add initial regmap infrastructure
Date: Thu, 16 Apr 2020 22:15:19 +0200 [thread overview]
Message-ID: <CAFqH_513KB+En_xbpXSBG6Q38kYxWCgw0KO3NVxCb6fqHDaKBA@mail.gmail.com> (raw)
In-Reply-To: <87lfmvjmt5.fsf@collabora.com>
Hi Adrian,
[snip]
> >>
> >> +static void dw_mipi_dsi_get_hw_version(struct dw_mipi_dsi
> >> *dsi) +{ + regmap_read(dsi->regs, DSI_VERSION,
> >> &dsi->hw_version); + dsi->hw_version &= VERSION; +
> >> if (!dsi->hw_version) + dev_err(dsi->dev, "Failed
> >> to read DSI hw version register\n");
> >
> > Is this an error that should be ignored? If you can't get the HW
> > version, probably, there is something wrong with your hardware
> > so, don't you need to return an error?
> >
>
> After thinking a bit more about it, that error should be a
> warning.
>
> I added it because in some cases (for eg. if the peripheral clock
> is disabled) the reads can return 0 which is obviously an invalid
> version and the bridge will error in the next step when not
> finding a layout.
>
If you'll error anyway, why wait? IIUC at this point the clock *must*
be enabled, and if not, something is wrong with the driver, I don't
see any advantage on delay the error. do you have a use case where
this is called and peripheral clock disabled?
> So I'll make this a warning in v7 and explicitely mention that
> reads version == 0 can be caused by a disabled pclk.
>
-- Enric
WARNING: multiple messages have this Message-ID (diff)
From: Enric Balletbo Serra <eballetbo@gmail.com>
To: Adrian Ratiu <adrian.ratiu@collabora.com>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Adrian Pop <pop.adrian61@gmail.com>,
Jonas Karlman <jonas@kwiboo.se>,
linux-kernel <linux-kernel@vger.kernel.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
Andrzej Hajda <a.hajda@samsung.com>,
"open list:ARM/Rockchip SoC..."
<linux-rockchip@lists.infradead.org>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Arnaud Ferraris <arnaud.ferraris@collabora.com>,
Collabora Kernel ML <kernel@collabora.com>,
Ezequiel Garcia <ezequiel@collabora.com>,
linux-stm32@st-md-mailman.stormreply.com,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-imx@nxp.com
Subject: Re: [PATCH v6 1/8] drm: bridge: dw_mipi_dsi: add initial regmap infrastructure
Date: Thu, 16 Apr 2020 22:15:19 +0200 [thread overview]
Message-ID: <CAFqH_513KB+En_xbpXSBG6Q38kYxWCgw0KO3NVxCb6fqHDaKBA@mail.gmail.com> (raw)
In-Reply-To: <87lfmvjmt5.fsf@collabora.com>
Hi Adrian,
[snip]
> >>
> >> +static void dw_mipi_dsi_get_hw_version(struct dw_mipi_dsi
> >> *dsi) +{ + regmap_read(dsi->regs, DSI_VERSION,
> >> &dsi->hw_version); + dsi->hw_version &= VERSION; +
> >> if (!dsi->hw_version) + dev_err(dsi->dev, "Failed
> >> to read DSI hw version register\n");
> >
> > Is this an error that should be ignored? If you can't get the HW
> > version, probably, there is something wrong with your hardware
> > so, don't you need to return an error?
> >
>
> After thinking a bit more about it, that error should be a
> warning.
>
> I added it because in some cases (for eg. if the peripheral clock
> is disabled) the reads can return 0 which is obviously an invalid
> version and the bridge will error in the next step when not
> finding a layout.
>
If you'll error anyway, why wait? IIUC at this point the clock *must*
be enabled, and if not, something is wrong with the driver, I don't
see any advantage on delay the error. do you have a use case where
this is called and peripheral clock disabled?
> So I'll make this a warning in v7 and explicitely mention that
> reads version == 0 can be caused by a disabled pclk.
>
-- Enric
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Enric Balletbo Serra <eballetbo@gmail.com>
To: Adrian Ratiu <adrian.ratiu@collabora.com>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Adrian Pop <pop.adrian61@gmail.com>,
Jonas Karlman <jonas@kwiboo.se>,
linux-kernel <linux-kernel@vger.kernel.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
Andrzej Hajda <a.hajda@samsung.com>,
"open list:ARM/Rockchip SoC..."
<linux-rockchip@lists.infradead.org>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Arnaud Ferraris <arnaud.ferraris@collabora.com>,
Collabora Kernel ML <kernel@collabora.com>,
Ezequiel Garcia <ezequiel@collabora.com>,
linux-stm32@st-md-mailman.stormreply.com,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-imx@nxp.com
Subject: Re: [PATCH v6 1/8] drm: bridge: dw_mipi_dsi: add initial regmap infrastructure
Date: Thu, 16 Apr 2020 22:15:19 +0200 [thread overview]
Message-ID: <CAFqH_513KB+En_xbpXSBG6Q38kYxWCgw0KO3NVxCb6fqHDaKBA@mail.gmail.com> (raw)
In-Reply-To: <87lfmvjmt5.fsf@collabora.com>
Hi Adrian,
[snip]
> >>
> >> +static void dw_mipi_dsi_get_hw_version(struct dw_mipi_dsi
> >> *dsi) +{ + regmap_read(dsi->regs, DSI_VERSION,
> >> &dsi->hw_version); + dsi->hw_version &= VERSION; +
> >> if (!dsi->hw_version) + dev_err(dsi->dev, "Failed
> >> to read DSI hw version register\n");
> >
> > Is this an error that should be ignored? If you can't get the HW
> > version, probably, there is something wrong with your hardware
> > so, don't you need to return an error?
> >
>
> After thinking a bit more about it, that error should be a
> warning.
>
> I added it because in some cases (for eg. if the peripheral clock
> is disabled) the reads can return 0 which is obviously an invalid
> version and the bridge will error in the next step when not
> finding a layout.
>
If you'll error anyway, why wait? IIUC at this point the clock *must*
be enabled, and if not, something is wrong with the driver, I don't
see any advantage on delay the error. do you have a use case where
this is called and peripheral clock disabled?
> So I'll make this a warning in v7 and explicitely mention that
> reads version == 0 can be caused by a disabled pclk.
>
-- Enric
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2020-04-16 20:24 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-14 15:19 [PATCH v6 0/8] Genericize DW MIPI DSI bridge and add i.MX 6 driver Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` [PATCH v6 1/8] drm: bridge: dw_mipi_dsi: add initial regmap infrastructure Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-15 15:53 ` Enric Balletbo Serra
2020-04-15 15:53 ` Enric Balletbo Serra
2020-04-15 15:53 ` Enric Balletbo Serra
2020-04-15 15:53 ` Enric Balletbo Serra
2020-04-16 18:25 ` Adrian Ratiu
2020-04-16 18:25 ` Adrian Ratiu
2020-04-16 18:25 ` Adrian Ratiu
2020-04-16 18:25 ` Adrian Ratiu
2020-04-16 18:41 ` Adrian Ratiu
2020-04-16 18:41 ` Adrian Ratiu
2020-04-16 18:41 ` Adrian Ratiu
2020-04-16 18:41 ` Adrian Ratiu
2020-04-16 20:15 ` Enric Balletbo Serra [this message]
2020-04-16 20:15 ` Enric Balletbo Serra
2020-04-16 20:15 ` Enric Balletbo Serra
2020-04-16 20:15 ` Enric Balletbo Serra
2020-04-17 8:07 ` Adrian Ratiu
2020-04-17 8:07 ` Adrian Ratiu
2020-04-17 8:07 ` Adrian Ratiu
2020-04-17 8:07 ` Adrian Ratiu
2020-04-14 15:19 ` [PATCH v6 2/8] drm: bridge: dw_mipi_dsi: abstract register access using reg_fields Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` [PATCH v6 3/8] drm: bridge: synopsis: add dsi v1.01 support Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` [PATCH v6 4/8] drm: imx: Add i.MX 6 MIPI DSI host platform driver Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-15 17:26 ` Enric Balletbo Serra
2020-04-15 17:26 ` Enric Balletbo Serra
2020-04-15 17:26 ` Enric Balletbo Serra
2020-04-15 17:26 ` Enric Balletbo Serra
2020-04-15 17:30 ` Laurent Pinchart
2020-04-15 17:30 ` Laurent Pinchart
2020-04-15 17:30 ` Laurent Pinchart
2020-04-15 17:30 ` Laurent Pinchart
2020-04-17 9:56 ` Adrian Ratiu
2020-04-17 9:56 ` Adrian Ratiu
2020-04-17 9:56 ` Adrian Ratiu
2020-04-17 9:56 ` Adrian Ratiu
2020-04-14 15:19 ` [PATCH v6 5/8] dt-bindings: display: add i.MX6 MIPI DSI host controller doc Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 20:42 ` Laurent Pinchart
2020-04-14 20:42 ` Laurent Pinchart
2020-04-14 20:42 ` Laurent Pinchart
2020-04-14 20:42 ` Laurent Pinchart
2020-04-15 11:28 ` Adrian Ratiu
2020-04-15 11:28 ` Adrian Ratiu
2020-04-15 11:28 ` Adrian Ratiu
2020-04-15 11:28 ` Adrian Ratiu
2020-04-14 15:19 ` [PATCH v6 6/8] drm: stm: dw-mipi-dsi: let the bridge handle the HW version check Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` [PATCH v6 7/8] drm: bridge: dw-mipi-dsi: split low power cfg register into fields Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` [PATCH v6 8/8] drm: bridge: dw-mipi-dsi: fix bad register field offsets Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
2020-04-14 15:19 ` Adrian Ratiu
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