drm/ast: Fix long time waiting on s3/s4 resume

In resume, DP's launch function, ast_dp_launch, could wait at most 30
seconds before timeout to check if DP is enabled. It could lead to 'DPM
device timeout' and trigger unrecoverable kernel panic.

To avoid this problem, we check if DP enable or not at driver probe only.

Reported-and-tested-by: Wendy Wang <wendy.wang@intel.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217278
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230530041240.13427-1-jammy_huang@aspeedtech.com

diff --git a/drivers/gpu/drm/ast/ast_dp.c b/drivers/gpu/drm/ast/ast_dp.c
index fbb070f63e36b8656bedfadea9b629dbad310f20..6dc1a09504e13ec2bad4bbf095c28a00b710d9e4 100644 (file)
--- a/drivers/gpu/drm/ast/ast_dp.c
+++ b/drivers/gpu/drm/ast/ast_dp.c
@@ -119,53 +119,32 @@ err_astdp_edid_not_ready:
 /*
  * Launch Aspeed DP
  */
-void ast_dp_launch(struct drm_device *dev, u8 bPower)
+void ast_dp_launch(struct drm_device *dev)
 {
-       u32 i = 0, j = 0, WaitCount = 1;
-       u8 bDPTX = 0;
+       u32 i = 0;
        u8 bDPExecute = 1;
-
        struct ast_device *ast = to_ast_device(dev);
-       // S3 come back, need more time to wait BMC ready.
-       if (bPower)
-               WaitCount = 300;
-
-
-       // Wait total count by different condition.
-       for (j = 0; j < WaitCount; j++) {
-               bDPTX = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xD1, TX_TYPE_MASK);
-
-               if (bDPTX)
-                       break;
 
+       // Wait one second then timeout.
+       while (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xD1, ASTDP_MCU_FW_EXECUTING) !=
+               ASTDP_MCU_FW_EXECUTING) {
+               i++;
+               // wait 100 ms
                msleep(100);
-       }
 
-       // 0xE : ASTDP with DPMCU FW handling
-       if (bDPTX == ASTDP_DPMCU_TX) {
-               // Wait one second then timeout.
-               i = 0;
-
-               while (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xD1, COPROCESSOR_LAUNCH) !=
-                       COPROCESSOR_LAUNCH) {
-                       i++;
-                       // wait 100 ms
-                       msleep(100);
-
-                       if (i >= 10) {
-                               // DP would not be ready.
-                               bDPExecute = 0;
-                               break;
-                       }
+               if (i >= 10) {
+                       // DP would not be ready.
+                       bDPExecute = 0;
+                       break;
                }
+       }
 
-               if (bDPExecute)
-                       ast->tx_chip_types |= BIT(AST_TX_ASTDP);
+       if (!bDPExecute)
+               drm_err(dev, "Wait DPMCU executing timeout\n");
 
-               ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xE5,
-                                                       (u8) ~ASTDP_HOST_EDID_READ_DONE_MASK,
-                                                       ASTDP_HOST_EDID_READ_DONE);
-       }
+       ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xE5,
+                              (u8) ~ASTDP_HOST_EDID_READ_DONE_MASK,
+                              ASTDP_HOST_EDID_READ_DONE);
 }
 
 

diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index a501169cddad890c0c845cf9217d8b517e16af94..5498a6676f2e8f2eede492b53c34e875ccf81635 100644 (file)
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -350,9 +350,6 @@ int ast_mode_config_init(struct ast_device *ast);
 #define AST_DP501_LINKRATE     0xf014
 #define AST_DP501_EDID_DATA    0xf020
 
-/* Define for Soc scratched reg */
-#define COPROCESSOR_LAUNCH                     BIT(5)
-
 /*
  * Display Transmitter Type:
  */
@@ -480,7 +477,7 @@ struct ast_i2c_chan *ast_i2c_create(struct drm_device *dev);
 
 /* aspeed DP */
 int ast_astdp_read_edid(struct drm_device *dev, u8 *ediddata);
-void ast_dp_launch(struct drm_device *dev, u8 bPower);
+void ast_dp_launch(struct drm_device *dev);
 void ast_dp_power_on_off(struct drm_device *dev, bool no);
 void ast_dp_set_on_off(struct drm_device *dev, bool no);
 void ast_dp_set_mode(struct drm_crtc *crtc, struct ast_vbios_mode_info *vbios_mode);

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index f32ce29edba726a903d7b082f770ae896bfce3cc..1f35438f614a7ba441af81e1e564da3ec1dd5d52 100644 (file)
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -254,8 +254,13 @@ static int ast_detect_chip(struct drm_device *dev, bool *need_post)
                case 0x0c:
                        ast->tx_chip_types = AST_TX_DP501_BIT;
                }
-       } else if (ast->chip == AST2600)
-               ast_dp_launch(&ast->base, 0);
+       } else if (ast->chip == AST2600) {
+               if (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xD1, TX_TYPE_MASK) ==
+                   ASTDP_DPMCU_TX) {
+                       ast->tx_chip_types = AST_TX_ASTDP_BIT;
+                       ast_dp_launch(&ast->base);
+               }
+       }
 
        /* Print stuff for diagnostic purposes */
        if (ast->tx_chip_types & AST_TX_NONE_BIT)
@@ -264,6 +269,8 @@ static int ast_detect_chip(struct drm_device *dev, bool *need_post)
                drm_info(dev, "Using Sil164 TMDS transmitter\n");
        if (ast->tx_chip_types & AST_TX_DP501_BIT)
                drm_info(dev, "Using DP501 DisplayPort transmitter\n");
+       if (ast->tx_chip_types & AST_TX_ASTDP_BIT)
+               drm_info(dev, "Using ASPEED DisplayPort transmitter\n");
 
        return 0;
 }

diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c
index 71bb36b865fdac627ac846ac210d7d1f3c0da5e4..a005aec18a0209a9bdb6e0dec252a750d3c99409 100644 (file)
--- a/drivers/gpu/drm/ast/ast_post.c
+++ b/drivers/gpu/drm/ast/ast_post.c
@@ -380,7 +380,8 @@ void ast_post_gpu(struct drm_device *dev)
        ast_set_def_ext_reg(dev);
 
        if (ast->chip == AST2600) {
-               ast_dp_launch(dev, 1);
+               if (ast->tx_chip_types & AST_TX_ASTDP_BIT)
+                       ast_dp_launch(dev);
        } else if (ast->config_mode == ast_use_p2a) {
                if (ast->chip == AST2500)
                        ast_post_chip_2500(dev);