From: Thierry Reding <thierry.reding@gmail.com>
To: bjorn@kryo.se
Cc: David Airlie <airlied@linux.ie>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 1/3] drm/dsi: Add support for Turn on/Shutdown peripheral packets
Date: Tue, 24 Nov 2015 10:33:56 +0100 [thread overview]
Message-ID: <20151124093356.GA6149@ulmo> (raw)
In-Reply-To: <1446251908-2603-1-git-send-email-bjorn@kryo.se>
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On Fri, Oct 30, 2015 at 05:38:26PM -0700, bjorn@kryo.se wrote:
> From: Werner Johansson <werner.johansson@sonymobile.com>
>
> The MIPI_DSI_TURN_ON_PERIPHERAL and MIPI_DSI_SHUTDOWN_PERIPHERAL
> packets are required for some panels, one example being the
> Panasonic VVX10F034N00 panel.
>
> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
> ---
> drivers/gpu/drm/drm_mipi_dsi.c | 47 ++++++++++++++++++++++++++++++++++++++++++
> include/drm/drm_mipi_dsi.h | 3 +++
> 2 files changed, 50 insertions(+)
This being a dependency on 3/3 it would've been good to send this To: me
as well. I hadn't seen this in my inbox and had simply discarded it as
being independent. Of course if I had properly checked the build I
would've noticed...
Anyway, I've applied this with slight modifications. I removed the raw
short write helper. I don't think it buys us much and we already have an
open-coded variant in mipi_dsi_set_maximum_return_packet_size(). I've
also moved these functions closer to the Set Maximum Return Packet Size
command implementation because they are part of the same command set. I
also made the functions return int instead of ssize_t to avoid potential
confusion about their return value (ssize_t implies "number of bytes
transferred, or a negative error code on failure).
One minor comment below...
> diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
> index 2d5ca8ee..13b4a9c 100644
> --- a/drivers/gpu/drm/drm_mipi_dsi.c
> +++ b/drivers/gpu/drm/drm_mipi_dsi.c
> @@ -862,6 +862,53 @@ int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
> }
> EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
>
> +/**
> + * mipi_dsi_raw_short_write() - Sends a data-less short DSI packet
> + * @dsi: DSI peripheral device
> + * @type: Data Type of packet to send
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +static ssize_t mipi_dsi_raw_short_write(struct mipi_dsi_device *dsi, u8 type)
> +{
> + u8 dummy[2] = { 0, 0 };
> + struct mipi_dsi_msg msg = {
> + .channel = dsi->channel,
> + .tx_buf = dummy,
> + .tx_len = sizeof(dummy),
> + .type = type
> + };
> +
> + if (mipi_dsi_packet_format_is_short(type))
> + return mipi_dsi_device_transfer(dsi, &msg);
> + else
> + return -1;
> +}
When the kerneldoc comment says "negative error code", developers will
expect one of the -E* constants. -1 maps to -EPERM (operation not
permitted), which isn't a good error code for this case. This is also an
internal function, so these errors really should never happen.
Anyway, since I removed this helper this isn't an issue anymore, just
wanted to mention it.
Thanks,
Thierry
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next prev parent reply other threads:[~2015-11-24 9:34 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-31 0:38 [PATCH 1/3] drm/dsi: Add support for Turn on/Shutdown peripheral packets bjorn
2015-10-31 0:38 ` [PATCH 2/3] panel/panasonic-vvx10f034n00: Add DT bindings bjorn
2015-11-02 15:59 ` Rob Herring
2015-11-23 11:32 ` Thierry Reding
2015-10-31 0:38 ` [PATCH 3/3] drm/panel: Add Panasonic VVX10F034N00 MIPI DSI panel bjorn
2015-11-22 1:08 ` Bjorn Andersson
2015-11-23 11:33 ` Thierry Reding
2015-11-23 20:46 ` Bjorn Andersson
2015-11-22 1:08 ` [PATCH 1/3] drm/dsi: Add support for Turn on/Shutdown peripheral packets Bjorn Andersson
2015-11-24 9:33 ` Thierry Reding [this message]
2015-11-24 16:02 ` Bjorn Andersson
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