From: Anusha Srivatsa asrivats@redhat.com
[ Upstream commit 20e8219205145e1af3b98b6a0a3cc59568116a05 ]
Move away from using deprecated API and use _multi variants if available. Use mipi_dsi_msleep() and mipi_dsi_usleep_range() instead of msleep() and usleep_range() respectively.
Used Coccinelle to find the _multi variant APIs,replacing mpi_dsi_msleep() where necessary and for returning dsi_ctx.accum_err in these functions. mipi_dsi_dcs_write() does not have a corresponding _multi() variant. Replacing it with mipi_dsi_dcs_write_seq_multi() instead. This change is manual.
The Coccinelle script is the same as the one in commit c8ba07caaecc ("drm/panel/synaptics-r63353: Use _multi variants")
v2: Use mipi_dsi_write_buffer_multi() in place of mipi_dsi_dcs_write(). (Dmitry)
v3: add commit details where the same coccinelle script is used and remove the actual script from commit log. Use mipi_dsi_dcs_write_seq_multi() for mipi_dsi_dcs_write() (Doug)
Cc: Maxime Ripard mripard@kernel.org Cc: Dmitry Baryshkov dmitry.baryshkov@linaro.org Cc: Tejas Vipin tejasvipin76@gmail.com Cc: Doug Anderson dianders@chromium.org Signed-off-by: Anusha Srivatsa asrivats@redhat.com Reviewed-by: Neil Armstrong neil.armstrong@linaro.org Reviewed-by: Douglas Anderson dianders@chromium.org Link: https://lore.kernel.org/r/20250326-b4-panel-ls043t1le01-v3-1-96c554c0ea2b@re... Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@oss.qualcomm.com Signed-off-by: Sasha Levin sashal@kernel.org ---
Looking at this commit, I need to analyze whether it should be backported to stable kernel trees. **Answer: NO** **Detailed Analysis:** This commit is a **code modernization/refactoring change** that converts from deprecated MIPI DSI APIs to newer "_multi" variants. Here's my detailed reasoning: ## 1. **Nature of Changes - API Modernization Only** The changes are purely about replacing deprecated function calls with their modern equivalents: - `mipi_dsi_dcs_exit_sleep_mode()` → `mipi_dsi_dcs_exit_sleep_mode_multi()` - `mipi_dsi_dcs_set_pixel_format()` → `mipi_dsi_dcs_set_pixel_format_multi()` - `mipi_dsi_dcs_set_display_on()` → `mipi_dsi_dcs_set_display_on_multi()` - `mipi_dsi_dcs_write()` → `mipi_dsi_dcs_write_seq_multi()` - `msleep()` → `mipi_dsi_msleep()` This is classic API modernization, not a bug fix. ## 2. **No Functional Bug Fixes** The commit doesn't address any user- visible issues, crashes, security vulnerabilities, or hardware compatibility problems. The panel functionality remains identical - this is purely about using preferred APIs for better error handling patterns. ## 3. **Pattern Consistent with Similar Commits** All the reference commits provided show the same pattern and are marked as **"Backport Status: NO"**: - **Similar Commit #1**: "Switch to mipi_dsi_dcs_write_seq_multi()" - mechanical conversion for code reduction - **Similar Commit #2**: "add more multi functions" - adding new API variants and deprecating old ones - **Similar Commit #4**: "Transition to mipi_dsi_dcs_write_seq_multi" - replacing deprecated macros - **Similar Commit #5**: "use mipi_dsi_dcs_nop_multi()" - removing conditional code using multi wrappers All these similar commits involve the same type of API modernization and none were backported. ## 4. **Error Handling Changes Don't Fix Existing Bugs** While the new "_multi" pattern provides better error handling through `dsi_ctx.accum_err`, the original code was already handling errors properly with explicit return checks. The change improves code maintainability but doesn't fix any error handling bugs. ## 5. **Stable Tree Criteria Violation** This commit violates stable tree rules: - **Not a critical bugfix**: No user-impacting issues resolved - **Introduces new features**: Uses newer API variants that may not exist in older kernels - **Code churn without necessity**: Changes working code for style/modernization reasons - **Potential compatibility issues**: "_multi" variants may not be available in all stable branches ## 6. **Risk vs. Benefit Analysis** - **Risk**: Potential incompatibility with older kernel versions, unnecessary code churn - **Benefit**: None for stable users - no bugs fixed, no new functionality for end users ## **Conclusion** This is a textbook example of a commit that should **NOT** be backported to stable trees. It's pure code modernization that doesn't fix any user-visible problems, follows the same pattern as other non-backported similar commits, and could potentially introduce compatibility issues in stable branches. Stable trees should only receive critical fixes, not API modernization changes.
.../gpu/drm/panel/panel-sharp-ls043t1le01.c | 41 +++++++------------ 1 file changed, 15 insertions(+), 26 deletions(-)
diff --git a/drivers/gpu/drm/panel/panel-sharp-ls043t1le01.c b/drivers/gpu/drm/panel/panel-sharp-ls043t1le01.c index 729cbb0d8403f..36abfa2e65e96 100644 --- a/drivers/gpu/drm/panel/panel-sharp-ls043t1le01.c +++ b/drivers/gpu/drm/panel/panel-sharp-ls043t1le01.c @@ -36,60 +36,49 @@ static inline struct sharp_nt_panel *to_sharp_nt_panel(struct drm_panel *panel) static int sharp_nt_panel_init(struct sharp_nt_panel *sharp_nt) { struct mipi_dsi_device *dsi = sharp_nt->dsi; - int ret; + struct mipi_dsi_multi_context dsi_ctx = { .dsi = dsi };
dsi->mode_flags |= MIPI_DSI_MODE_LPM;
- ret = mipi_dsi_dcs_exit_sleep_mode(dsi); - if (ret < 0) - return ret; + mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
- msleep(120); + mipi_dsi_msleep(&dsi_ctx, 120);
/* Novatek two-lane operation */ - ret = mipi_dsi_dcs_write(dsi, 0xae, (u8[]){ 0x03 }, 1); - if (ret < 0) - return ret; + mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xae, 0x03);
/* Set both MCU and RGB I/F to 24bpp */ - ret = mipi_dsi_dcs_set_pixel_format(dsi, MIPI_DCS_PIXEL_FMT_24BIT | - (MIPI_DCS_PIXEL_FMT_24BIT << 4)); - if (ret < 0) - return ret; + mipi_dsi_dcs_set_pixel_format_multi(&dsi_ctx, + MIPI_DCS_PIXEL_FMT_24BIT | + (MIPI_DCS_PIXEL_FMT_24BIT << 4));
- return 0; + return dsi_ctx.accum_err; }
static int sharp_nt_panel_on(struct sharp_nt_panel *sharp_nt) { struct mipi_dsi_device *dsi = sharp_nt->dsi; - int ret; + struct mipi_dsi_multi_context dsi_ctx = { .dsi = dsi };
dsi->mode_flags |= MIPI_DSI_MODE_LPM;
- ret = mipi_dsi_dcs_set_display_on(dsi); - if (ret < 0) - return ret; + mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
- return 0; + return dsi_ctx.accum_err; }
static int sharp_nt_panel_off(struct sharp_nt_panel *sharp_nt) { struct mipi_dsi_device *dsi = sharp_nt->dsi; - int ret; + struct mipi_dsi_multi_context dsi_ctx = { .dsi = dsi };
dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
- ret = mipi_dsi_dcs_set_display_off(dsi); - if (ret < 0) - return ret; + mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
- ret = mipi_dsi_dcs_enter_sleep_mode(dsi); - if (ret < 0) - return ret; + mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
- return 0; + return dsi_ctx.accum_err; }
static int sharp_nt_panel_unprepare(struct drm_panel *panel)