From 95fe25306512b93a48f05bc874f8ce742eabef97 Mon Sep 17 00:00:00 2001
From: morris <maoshengrong@espressif.com>
Date: Tue, 25 Feb 2025 15:40:12 +0800
Subject: [PATCH] feat(gdma): allow bypass the alignment check in the link
 driver

Closes https://github.com/espressif/esp-idf/issues/15228
---
 components/esp_hw_support/dma/gdma_link.c                     | 4 +++-
 components/esp_hw_support/dma/include/esp_private/gdma_link.h | 2 ++
 components/esp_lcd/rgb/esp_lcd_panel_rgb.c                    | 1 +
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/components/esp_hw_support/dma/gdma_link.c b/components/esp_hw_support/dma/gdma_link.c
index 6b141e9cda..29288decf1 100644
--- a/components/esp_hw_support/dma/gdma_link.c
+++ b/components/esp_hw_support/dma/gdma_link.c
@@ -166,7 +166,9 @@ esp_err_t gdma_link_mount_buffers(gdma_link_list_handle_t list, int start_item_i
         uint8_t *buf = (uint8_t *)config->buffer;
         size_t len = config->length;
         // check the buffer alignment
-        ESP_RETURN_ON_FALSE(((uintptr_t)buf & (buffer_alignment - 1)) == 0, ESP_ERR_INVALID_ARG, TAG, "buffer not aligned to %zu", buffer_alignment);
+        if (!config->flags.bypass_buffer_align_check) {
+            ESP_RETURN_ON_FALSE(((uintptr_t)buf & (buffer_alignment - 1)) == 0, ESP_ERR_INVALID_ARG, TAG, "buffer not aligned to %zu", buffer_alignment);
+        }
         uint32_t num_items_need = (len + max_buffer_mount_length - 1) / max_buffer_mount_length;
         // check if there are enough link list items
         ESP_RETURN_ON_FALSE((begin_item_idx + num_items_need) <= (start_item_index + num_items_avail), ESP_ERR_INVALID_ARG, TAG, "no more space for buffer mounting");
diff --git a/components/esp_hw_support/dma/include/esp_private/gdma_link.h b/components/esp_hw_support/dma/include/esp_private/gdma_link.h
index 6972d16d16..7ab326edcc 100644
--- a/components/esp_hw_support/dma/include/esp_private/gdma_link.h
+++ b/components/esp_hw_support/dma/include/esp_private/gdma_link.h
@@ -72,6 +72,8 @@ typedef struct {
                                      Note, DMA engine will stop at this item and trigger an interrupt.
                                      If `mark_final` is not set, this list item will point to the next item, and
                                      wrap around to the head item if it's the last one in the list. */
+        uint32_t bypass_buffer_align_check: 1; /*!< Whether to bypass the buffer alignment check.
+                                                    Only enable it when you know what you are doing. */
     } flags; //!< Flags for buffer mount configurations
 } gdma_buffer_mount_config_t;
 
diff --git a/components/esp_lcd/rgb/esp_lcd_panel_rgb.c b/components/esp_lcd/rgb/esp_lcd_panel_rgb.c
index 2a1b691bbd..4df1d816d6 100644
--- a/components/esp_lcd/rgb/esp_lcd_panel_rgb.c
+++ b/components/esp_lcd/rgb/esp_lcd_panel_rgb.c
@@ -1000,6 +1000,7 @@ static esp_err_t lcd_rgb_panel_init_trans_link(esp_rgb_panel_t *rgb_panel)
         gdma_buffer_mount_config_t restart_buffer_mount_cfg = {
             .buffer = rgb_panel->fbs[0] + restart_skip_bytes,
             .length = MIN(LCD_DMA_DESCRIPTOR_BUFFER_MAX_SIZE, rgb_panel->fb_size) - restart_skip_bytes,
+            .flags.bypass_buffer_align_check = true, // the restart buffer may doesn't match the buffer alignment but it doesn't really matter in this case
         };
         ESP_RETURN_ON_ERROR(gdma_link_mount_buffers(rgb_panel->dma_restart_link, 0, &restart_buffer_mount_cfg, 1, NULL),
                             TAG, "mount DMA restart buffer failed");