From: Neil Armstrong <neil.armstrong@linaro.org>
To: Douglas Anderson <dianders@chromium.org>,
dri-devel@lists.freedesktop.org
Cc: Javier Martinez Canillas <javierm@redhat.com>,
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
linus.walleij@linaro.org,
Cong Yang <yangcong5@huaqin.corp-partner.google.com>,
lvzhaoxiong@huaqin.corp-partner.google.com,
Hsin-Yi Wang <hsinyi@google.com>, Sam Ravnborg <sam@ravnborg.org>,
Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@gmail.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drm/mipi-dsi: Reduce driver bloat of mipi_dsi_*_write_seq()
Date: Thu, 25 Apr 2024 09:55:11 +0200 [thread overview]
Message-ID: <300eab2e-f884-4978-9f19-b764bb5fb47a@linaro.org> (raw)
In-Reply-To: <20240424172017.1.Id15fae80582bc74a0d4f1338987fa375738f45b9@changeid>
On 25/04/2024 02:20, Douglas Anderson wrote:
> The consensus of many DRM folks is that we want to move away from DSI
> drivers defining tables of init commands. Instead, we want to move to
> init functions that can use common DRM functions. The issue thus far
> has been that using the macros mipi_dsi_generic_write_seq() and
> mipi_dsi_dcs_write_seq() bloats the driver using them.
>
> Through a cooperative effort between Hsin-Yi Wang and Dmitry
> Baryshkov, we have realized that the majority of the bloat is the fact
> that we have the dev_err_ratelimited() directly in the macros. Let's
> hoist this call into drm_mipi_dsi.c by adding a "chatty" version of
> the functions that includes the print.
>
> Without any changes to clients this gives a dramatic savings. Building
> with my build system shows one example:
>
> $ scripts/bloat-o-meter \
> .../before/panel-novatek-nt36672e.ko \
> .../after/panel-novatek-nt36672e.ko
>
> add/remove: 0/1 grow/shrink: 1/1 up/down: 6/-19652 (-19646)
> Function old new delta
> __UNIQUE_ID_vermagic520 64 70 +6
> nt36672e_1080x2408_60hz_init 16592 7260 -9332
> nt36672e_1080x2408_60hz_init._rs 10320 - -10320
> Total: Before=31503, After=11857, chg -62.36%
>
> Note that given the change in location of the print it's harder to
> include the "cmd" in the printout for mipi_dsi_dcs_write_seq() since,
> theoretically, someone could call the new chatty function with a
> zero-size array and it would be illegal to dereference data[0].
> There's a printk format to print the whole buffer and this is probably
> more useful for debugging anyway. Given that we're doing this for
> mipi_dsi_dcs_write_seq(), let's also print the buffer for
> mipi_dsi_generic_write_seq() in the error case.
>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> The MIPI device I have in front of me (wormdingler) hasn't been
> converted to use these functions yet, so this is just compile
> tested. It's about my end of day so I'm sending this out since it's
> pretty straightforward. Hopefully others can confirm it works well for
> them and also saves space under their compilers.
>
> drivers/gpu/drm/drm_mipi_dsi.c | 54 ++++++++++++++++++++++++++++++++++
> include/drm/drm_mipi_dsi.h | 31 ++++++++-----------
> 2 files changed, 67 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
> index 795001bb7ff1..5ded6aef38ed 100644
> --- a/drivers/gpu/drm/drm_mipi_dsi.c
> +++ b/drivers/gpu/drm/drm_mipi_dsi.c
> @@ -764,6 +764,33 @@ ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
> }
> EXPORT_SYMBOL(mipi_dsi_generic_write);
>
> +/**
> + * mipi_dsi_generic_write_chatty() - mipi_dsi_generic_write() w/ an error log
> + * @dsi: DSI peripheral device
> + * @payload: buffer containing the payload
> + * @size: size of payload buffer
> + *
> + * Just like mipi_dsi_generic_write() but includes a dev_err_ratelimited()
> + * call for you.
> + *
> + * Return: The number of bytes transmitted on success or a negative error code
> + * on failure.
> + */
> +ssize_t mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi,
> + const void *payload, size_t size)
> +{
> + struct device *dev = &dsi->dev;
> + int ret;
> +
> + ret = mipi_dsi_generic_write(dsi, payload, size);
> + if (ret < 0)
> + dev_err_ratelimited(dev, "sending generic data %*ph failed: %d\n",
> + (int)size, payload, ret);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(mipi_dsi_generic_write_chatty);
> +
> /**
> * mipi_dsi_generic_read() - receive data using a generic read packet
> * @dsi: DSI peripheral device
> @@ -852,6 +879,33 @@ ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
> }
> EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer);
>
> +/**
> + * mipi_dsi_dcs_write_buffer_chatty - mipi_dsi_dcs_write_buffer() w/ an error log
> + * @dsi: DSI peripheral device
> + * @data: buffer containing data to be transmitted
> + * @len: size of transmission buffer
> + *
> + * Just like mipi_dsi_dcs_write_buffer() but includes a dev_err_ratelimited()
> + * call for you.
> + *
> + * Return: The number of bytes successfully transmitted or a negative error
> + * code on failure.
> + */
> +ssize_t mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi,
> + const void *data, size_t len)
> +{
> + struct device *dev = &dsi->dev;
> + int ret;
> +
> + ret = mipi_dsi_dcs_write_buffer(dsi, data, len);
> + if (ret < 0)
> + dev_err_ratelimited(dev, "sending dcs data %*ph failed: %d\n",
> + (int)len, data, ret);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer_chatty);
> +
> /**
> * mipi_dsi_dcs_write() - send DCS write command
> * @dsi: DSI peripheral device
> diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
> index 82b1cc434ea3..784e425dc4c8 100644
> --- a/include/drm/drm_mipi_dsi.h
> +++ b/include/drm/drm_mipi_dsi.h
> @@ -256,6 +256,8 @@ int mipi_dsi_picture_parameter_set(struct mipi_dsi_device *dsi,
>
> ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
> size_t size);
> +ssize_t mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi,
> + const void *payload, size_t size);
> ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
> size_t num_params, void *data, size_t size);
>
> @@ -279,6 +281,8 @@ enum mipi_dsi_dcs_tear_mode {
>
> ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
> const void *data, size_t len);
> +ssize_t mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi,
> + const void *data, size_t len);
> ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
> const void *data, size_t len);
> ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
> @@ -317,14 +321,10 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi,
> #define mipi_dsi_generic_write_seq(dsi, seq...) \
> do { \
> static const u8 d[] = { seq }; \
> - struct device *dev = &dsi->dev; \
> int ret; \
> - ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d)); \
> - if (ret < 0) { \
> - dev_err_ratelimited(dev, "transmit data failed: %d\n", \
> - ret); \
> + ret = mipi_dsi_generic_write_chatty(dsi, d, ARRAY_SIZE(d)); \
> + if (ret < 0) \
> return ret; \
> - } \
> } while (0)
>
> /**
> @@ -333,18 +333,13 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi,
> * @cmd: Command
> * @seq: buffer containing data to be transmitted
> */
> -#define mipi_dsi_dcs_write_seq(dsi, cmd, seq...) \
> - do { \
> - static const u8 d[] = { cmd, seq }; \
> - struct device *dev = &dsi->dev; \
> - int ret; \
> - ret = mipi_dsi_dcs_write_buffer(dsi, d, ARRAY_SIZE(d)); \
> - if (ret < 0) { \
> - dev_err_ratelimited( \
> - dev, "sending command %#02x failed: %d\n", \
> - cmd, ret); \
> - return ret; \
> - } \
> +#define mipi_dsi_dcs_write_seq(dsi, cmd, seq...) \
> + do { \
> + static const u8 d[] = { cmd, seq }; \
> + int ret; \
> + ret = mipi_dsi_dcs_write_buffer_chatty(dsi, d, ARRAY_SIZE(d)); \
> + if (ret < 0) \
> + return ret; \
> } while (0)
>
> /**
At first sight it looks o for me, it's less efficient since it adds a function call
for each sequence, but the saving if very significant.
I'll run a test on the vtdr6130 to be sure.
Neil
next prev parent reply other threads:[~2024-04-25 7:55 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-25 0:20 [PATCH] drm/mipi-dsi: Reduce driver bloat of mipi_dsi_*_write_seq() Douglas Anderson
2024-04-25 7:55 ` Neil Armstrong [this message]
2024-04-25 8:19 ` Jani Nikula
2024-04-25 17:04 ` Doug Anderson
2024-04-26 3:03 ` Dmitry Baryshkov
2024-04-26 15:35 ` Doug Anderson
2024-04-26 15:42 ` Dmitry Baryshkov
2024-04-26 10:08 ` Jani Nikula
2024-04-26 15:28 ` Doug Anderson
2024-04-27 0:01 ` Doug Anderson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=300eab2e-f884-4978-9f19-b764bb5fb47a@linaro.org \
--to=neil.armstrong@linaro.org \
--cc=airlied@gmail.com \
--cc=daniel@ffwll.ch \
--cc=dianders@chromium.org \
--cc=dmitry.baryshkov@linaro.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=hsinyi@google.com \
--cc=javierm@redhat.com \
--cc=linus.walleij@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lvzhaoxiong@huaqin.corp-partner.google.com \
--cc=maarten.lankhorst@linux.intel.com \
--cc=mripard@kernel.org \
--cc=sam@ravnborg.org \
--cc=tzimmermann@suse.de \
--cc=yangcong5@huaqin.corp-partner.google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.