* [PATCH 2/4] drm/mipi-dsi: remove deprecated write_seq macro and chatty helper
2025-09-21 18:37 [PATCH 1/4] drm/panel/lpm102a188a: Switch to mipi_dsi_generic_write_seq_multi() rtapadia730
@ 2025-09-21 18:37 ` rtapadia730
2025-09-21 18:37 ` [PATCH 3/4] drm/mipi-dsi: remove deprecated mipi_dsi_dcs_write_buffer_chatty rtapadia730
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: rtapadia730 @ 2025-09-21 18:37 UTC (permalink / raw)
To: neil.armstrong, maarten.lankhorst
Cc: mripard, tzimmermann, airlied, simona, jessica.zhang, dri-devel,
linux-kernel, linux-doc, corbet, Rajeev Tapadia
From: Rajeev Tapadia <rtapadia730@gmail.com>
The mipi_dsi_generic_write_seq() macro is non-intuitive because it
returns out of the caller on error, leading to subtle bugs in panel
drivers. Similarly, mipi_dsi_generic_write_chatty() is redundant.
Both are removed in favour of mipi_dsi_generic_write_multi(), which
provides proper error accumulation for multiple DSI writes and is safer
for panel drivers.
Signed-off-by: Rajeev Tapadia <rtapadia730@gmail.com>
---
drivers/gpu/drm/drm_mipi_dsi.c | 32 +++-----------------------------
include/drm/drm_mipi_dsi.h | 23 -----------------------
2 files changed, 3 insertions(+), 52 deletions(-)
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 3a9b3278a6e3..bc847ab5c822 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -773,42 +773,16 @@ 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
+ * mipi_dsi_generic_write_multi()
+ * @ctx: Context for multiple DSI transactions
* @payload: buffer containing the payload
* @size: size of payload buffer
*
* Like mipi_dsi_generic_write() but includes a dev_err()
- * call for you and returns 0 upon success, not the number of bytes sent.
+ * call for you.
*
* Return: 0 on success or a negative error code on failure.
*/
-int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi,
- const void *payload, size_t size)
-{
- struct device *dev = &dsi->dev;
- ssize_t ret;
-
- ret = mipi_dsi_generic_write(dsi, payload, size);
- if (ret < 0) {
- dev_err(dev, "sending generic data %*ph failed: %zd\n",
- (int)size, payload, ret);
- return ret;
- }
-
- return 0;
-}
-EXPORT_SYMBOL(mipi_dsi_generic_write_chatty);
-
-/**
- * mipi_dsi_generic_write_multi() - mipi_dsi_generic_write_chatty() w/ accum_err
- * @ctx: Context for multiple DSI transactions
- * @payload: buffer containing the payload
- * @size: size of payload buffer
- *
- * Like mipi_dsi_generic_write_chatty() but deals with errors in a way that
- * makes it convenient to make several calls in a row.
- */
void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx,
const void *payload, size_t size)
{
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 57a869a6f6e8..e4d26ed7a62a 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -288,8 +288,6 @@ void mipi_dsi_picture_parameter_set_multi(struct mipi_dsi_multi_context *ctx,
ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
size_t size);
-int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi,
- const void *payload, size_t size);
void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx,
const void *payload, size_t size);
ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
@@ -382,27 +380,6 @@ void mipi_dsi_dcs_set_tear_scanline_multi(struct mipi_dsi_multi_context *ctx,
u16 scanline);
void mipi_dsi_dcs_set_tear_off_multi(struct mipi_dsi_multi_context *ctx);
-/**
- * mipi_dsi_generic_write_seq - transmit data using a generic write packet
- *
- * This macro will print errors for you and will RETURN FROM THE CALLING
- * FUNCTION (yes this is non-intuitive) upon error.
- *
- * Because of the non-intuitive return behavior, THIS MACRO IS DEPRECATED.
- * Please replace calls of it with mipi_dsi_generic_write_seq_multi().
- *
- * @dsi: DSI peripheral device
- * @seq: buffer containing the payload
- */
-#define mipi_dsi_generic_write_seq(dsi, seq...) \
- do { \
- static const u8 d[] = { seq }; \
- int ret; \
- ret = mipi_dsi_generic_write_chatty(dsi, d, ARRAY_SIZE(d)); \
- if (ret < 0) \
- return ret; \
- } while (0)
-
/**
* mipi_dsi_generic_write_seq_multi - transmit data using a generic write packet
*
--
2.51.0
Test message
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/4] drm/mipi-dsi: remove deprecated mipi_dsi_dcs_write_buffer_chatty
2025-09-21 18:37 [PATCH 1/4] drm/panel/lpm102a188a: Switch to mipi_dsi_generic_write_seq_multi() rtapadia730
2025-09-21 18:37 ` [PATCH 2/4] drm/mipi-dsi: remove deprecated write_seq macro and chatty helper rtapadia730
@ 2025-09-21 18:37 ` rtapadia730
2025-09-21 18:37 ` [PATCH 4/4] drm/todo: remove todo entry for deprecated mipi_dsi_*_write_seq() rtapadia730
2025-10-29 20:35 ` [PATCH 1/4] drm/panel/lpm102a188a: Switch to mipi_dsi_generic_write_seq_multi() neil.armstrong
3 siblings, 0 replies; 5+ messages in thread
From: rtapadia730 @ 2025-09-21 18:37 UTC (permalink / raw)
To: neil.armstrong, maarten.lankhorst
Cc: mripard, tzimmermann, airlied, simona, jessica.zhang, dri-devel,
linux-kernel, linux-doc, corbet, Rajeev Tapadia
From: Rajeev Tapadia <rtapadia730@gmail.com>
The mipi_dsi_dcs_write_buffer_chatty() helper is redundant and
non-intuitive. It has been removed in favour of
mipi_dsi_dcs_write_buffer_multi(), which handles multiple DSI writes with
proper error accumulation.
Signed-off-by: Rajeev Tapadia <rtapadia730@gmail.com>
---
drivers/gpu/drm/drm_mipi_dsi.c | 32 ++------------------------------
include/drm/drm_mipi_dsi.h | 2 --
2 files changed, 2 insertions(+), 32 deletions(-)
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index bc847ab5c822..c2fcc219cb58 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -926,40 +926,12 @@ 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
- *
- * Like mipi_dsi_dcs_write_buffer() but includes a dev_err()
- * call for you and returns 0 upon success, not the number of bytes sent.
- *
- * Return: 0 on success or a negative error code on failure.
- */
-int mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi,
- const void *data, size_t len)
-{
- struct device *dev = &dsi->dev;
- ssize_t ret;
-
- ret = mipi_dsi_dcs_write_buffer(dsi, data, len);
- if (ret < 0) {
- dev_err(dev, "sending dcs data %*ph failed: %zd\n",
- (int)len, data, ret);
- return ret;
- }
-
- return 0;
-}
-EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer_chatty);
-
-/**
- * mipi_dsi_dcs_write_buffer_multi - mipi_dsi_dcs_write_buffer_chatty() w/ accum_err
+ * mipi_dsi_dcs_write_buffer_multi - mipi_dsi_dcs_write_buffer() w/ accum_err
* @ctx: Context for multiple DSI transactions
* @data: buffer containing data to be transmitted
* @len: size of transmission buffer
*
- * Like mipi_dsi_dcs_write_buffer_chatty() but deals with errors in a way that
+ * Like mipi_dsi_dcs_write_buffer() but deals with errors in a way that
* makes it convenient to make several calls in a row.
*/
void mipi_dsi_dcs_write_buffer_multi(struct mipi_dsi_multi_context *ctx,
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index e4d26ed7a62a..cda981a41bc6 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -326,8 +326,6 @@ enum mipi_dsi_dcs_tear_mode {
ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
const void *data, size_t len);
-int mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi,
- const void *data, size_t len);
void mipi_dsi_dcs_write_buffer_multi(struct mipi_dsi_multi_context *ctx,
const void *data, size_t len);
ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
--
2.51.0
Test patch
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 4/4] drm/todo: remove todo entry for deprecated mipi_dsi_*_write_seq()
2025-09-21 18:37 [PATCH 1/4] drm/panel/lpm102a188a: Switch to mipi_dsi_generic_write_seq_multi() rtapadia730
2025-09-21 18:37 ` [PATCH 2/4] drm/mipi-dsi: remove deprecated write_seq macro and chatty helper rtapadia730
2025-09-21 18:37 ` [PATCH 3/4] drm/mipi-dsi: remove deprecated mipi_dsi_dcs_write_buffer_chatty rtapadia730
@ 2025-09-21 18:37 ` rtapadia730
2025-10-29 20:35 ` [PATCH 1/4] drm/panel/lpm102a188a: Switch to mipi_dsi_generic_write_seq_multi() neil.armstrong
3 siblings, 0 replies; 5+ messages in thread
From: rtapadia730 @ 2025-09-21 18:37 UTC (permalink / raw)
To: neil.armstrong, maarten.lankhorst
Cc: mripard, tzimmermann, airlied, simona, jessica.zhang, dri-devel,
linux-kernel, linux-doc, corbet, Rajeev Tapadia
From: Rajeev Tapadia <rtapadia730@gmail.com>
The todo entry about transitioning from mipi_dsi_*_write_seq() is
completed.
Signed-off-by: Rajeev Tapadia <rtapadia730@gmail.com>
---
Documentation/gpu/todo.rst | 18 ------------------
1 file changed, 18 deletions(-)
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index be8637da3fe9..76afb8a784e3 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -497,24 +497,6 @@ Contact: Douglas Anderson <dianders@chromium.org>
Level: Intermediate
-Transition away from using mipi_dsi_*_write_seq()
--------------------------------------------------
-
-The macros mipi_dsi_generic_write_seq() and mipi_dsi_dcs_write_seq() are
-non-intuitive because, if there are errors, they return out of the *caller's*
-function. We should move all callers to use mipi_dsi_generic_write_seq_multi()
-and mipi_dsi_dcs_write_seq_multi() macros instead.
-
-Once all callers are transitioned, the macros and the functions that they call,
-mipi_dsi_generic_write_chatty() and mipi_dsi_dcs_write_buffer_chatty(), can
-probably be removed. Alternatively, if people feel like the _multi() variants
-are overkill for some use cases, we could keep the mipi_dsi_*_write_seq()
-variants but change them not to return out of the caller.
-
-Contact: Douglas Anderson <dianders@chromium.org>
-
-Level: Starter
-
Remove devm_drm_put_bridge()
----------------------------
--
2.51.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 1/4] drm/panel/lpm102a188a: Switch to mipi_dsi_generic_write_seq_multi()
2025-09-21 18:37 [PATCH 1/4] drm/panel/lpm102a188a: Switch to mipi_dsi_generic_write_seq_multi() rtapadia730
` (2 preceding siblings ...)
2025-09-21 18:37 ` [PATCH 4/4] drm/todo: remove todo entry for deprecated mipi_dsi_*_write_seq() rtapadia730
@ 2025-10-29 20:35 ` neil.armstrong
3 siblings, 0 replies; 5+ messages in thread
From: neil.armstrong @ 2025-10-29 20:35 UTC (permalink / raw)
To: rtapadia730, maarten.lankhorst
Cc: mripard, tzimmermann, airlied, simona, jessica.zhang, dri-devel,
linux-kernel, linux-doc, corbet
On 9/21/25 20:37, rtapadia730@gmail.com wrote:
> From: Rajeev Tapadia <rtapadia730@gmail.com>
>
> Replace deprecated mipi_dsi_generic_write_seq() calls with
> mipi_dsi_generic_write_seq_multi(). This avoids hidden early returns
> and matches the direction of other panel drivers.
>
> No functional change intended.
>
> Signed-off-by: Rajeev Tapadia <rtapadia730@gmail.com>
> ---
>
> Question for reviewers:
> In this patch, I switched to using mipi_dsi_generic_write_seq_multi().
> Currently, if both link1 and link2 return errors, only one error is
> reported via accum_err. How should this ideally be handled? Should we
> report the first error, the last, or combine them somehow?
No it's fine, the first error is catched and reported.
The good way to do this is via this macro:
#define mipi_dsi_dual_dcs_write_seq_multi(dsi_ctx, dsi0, dsi1, cmd, seq...) \
do { \
dsi_ctx.dsi = dsi0; \
mipi_dsi_dcs_write_seq_multi(&dsi_ctx, cmd, seq); \
dsi_ctx.dsi = dsi1; \
mipi_dsi_dcs_write_seq_multi(&dsi_ctx, cmd, seq); \
} while (0)
with a single context. The mipi_dsi_dcs_write_seq_multi will print the
error from the proper DSI and the context will have the appropriate error.
Neil
>
> drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c b/drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c
> index 5f897e143758..982cb61849a0 100644
> --- a/drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c
> +++ b/drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c
> @@ -162,27 +162,34 @@ static int jdi_setup_symmetrical_split(struct mipi_dsi_device *left,
> static int jdi_write_dcdc_registers(struct jdi_panel *jdi)
> {
> /* Clear the manufacturer command access protection */
> - mipi_dsi_generic_write_seq(jdi->link1, MCS_CMD_ACS_PROT,
> + struct mipi_dsi_multi_context dsi_ctx1 = {.dsi = jdi->link1};
> + struct mipi_dsi_multi_context dsi_ctx2 = {.dsi = jdi->link2};
> +
> + mipi_dsi_generic_write_seq_multi(&dsi_ctx1, MCS_CMD_ACS_PROT,
> MCS_CMD_ACS_PROT_OFF);
> - mipi_dsi_generic_write_seq(jdi->link2, MCS_CMD_ACS_PROT,
> + mipi_dsi_generic_write_seq_multi(&dsi_ctx2, MCS_CMD_ACS_PROT,
> MCS_CMD_ACS_PROT_OFF);
> /*
> * Change the VGH/VGL divide rations to move the noise generated by the
> * TCONN. This should hopefully avoid interaction with the backlight
> * controller.
> */
> - mipi_dsi_generic_write_seq(jdi->link1, MCS_PWR_CTRL_FUNC,
> + mipi_dsi_generic_write_seq_multi(&dsi_ctx1, MCS_PWR_CTRL_FUNC,
> MCS_PWR_CTRL_PARAM1_VGH_330_DIV |
> MCS_PWR_CTRL_PARAM1_DEFAULT,
> MCS_PWR_CTRL_PARAM2_VGL_410_DIV |
> MCS_PWR_CTRL_PARAM2_DEFAULT);
>
> - mipi_dsi_generic_write_seq(jdi->link2, MCS_PWR_CTRL_FUNC,
> + mipi_dsi_generic_write_seq_multi(&dsi_ctx2, MCS_PWR_CTRL_FUNC,
> MCS_PWR_CTRL_PARAM1_VGH_330_DIV |
> MCS_PWR_CTRL_PARAM1_DEFAULT,
> MCS_PWR_CTRL_PARAM2_VGL_410_DIV |
> MCS_PWR_CTRL_PARAM2_DEFAULT);
>
> + if (dsi_ctx1.accum_err < 0)
> + return dsi_ctx1.accum_err;
> + if (dsi_ctx2.accum_err < 0)
> + return dsi_ctx2.accum_err;
> return 0;
> }
>
^ permalink raw reply [flat|nested] 5+ messages in thread