RE: [PATCH v4] drm/ast: Disable fast reset after DRAM initial

From: Kuo-Hsiang Chou
Date: Mon Jun 21 2021 - 07:06:09 EST

Hi Thomas,

May I know if I need to port this patch to the latest drm-misc-next again, because the patch has send to review for a while.
If the porting or any other thing can reduce your review effort, please instruct me. Thanks!

Best Regards,
Kuo-Hsiang Chou

-----Original Message-----
From: dri-devel [mailto:dri-devel-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf Of Kuo-Hsiang Chou
Sent: Wednesday, May 26, 2021 6:24 PM
To: tzimmermann@xxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: RE: [PATCH v4] drm/ast: Disable fast reset after DRAM initial



-----Original Message-----
From: Kuo-Hsiang Chou
Sent: Friday, May 07, 2021 5:27 PM
To: tzimmermann@xxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Cc: airlied@xxxxxxxxxx; airlied@xxxxxxxx; daniel@xxxxxxxx; Jenmin Yuan <jenmin_yuan@xxxxxxxxxxxxxx>; Kuo-Hsiang Chou <kuohsiang_chou@xxxxxxxxxxxxxx>; Arc Sung <arc_sung@xxxxxxxxxxxxxx>
Subject: [PATCH v4] drm/ast: Disable fast reset after DRAM initial

Hi Thomas,

May I know if this patch has sth wrong. Or something I need to improve on it, I can fix it right now. Thanks!

Regards,
Kuo-Hsiang Chou

[Bug][AST2500]

V1:
When AST2500 acts as stand-alone VGA so that DRAM and DVO initialization have to be achieved by VGA driver with P2A (PCI to AHB) enabling.
However, HW suggests disable Fast reset mode after DRAM initializaton, because fast reset mode is mainly designed for ARM ICE debugger.
Once Fast reset is checked as enabling, WDT (Watch Dog Timer) should be first enabled to avoid system deadlock before disable fast reset mode.

V2:
Use to_pci_dev() to get revision of PCI configuration.

V3:
If SCU00 is not unlocked, just enter its password again.
It is unnecessary to clear AHB lock condition and restore WDT default setting again, before Fast-reset clearing.

V4:
repatch after "error : could not build fake ancestor" resolved.

Signed-off-by: KuoHsiang Chou <kuohsiang_chou@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/ast/ast_drv.h | 1 +
drivers/gpu/drm/ast/ast_main.c | 4 ++
drivers/gpu/drm/ast/ast_post.c | 68 +++++++++++++++++++++-------------
3 files changed, 47 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h index 911f9f414..5ebb5905d 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -346,6 +346,7 @@ bool ast_is_vga_enabled(struct drm_device *dev); void ast_post_gpu(struct drm_device *dev);
u32 ast_mindwm(struct ast_private *ast, u32 r); void ast_moutdwm(struct ast_private *ast, u32 r, u32 v);
+void ast_patch_ahb_2500(struct ast_private *ast);
/* ast dp501 */
void ast_set_dp501_video_output(struct drm_device *dev, u8 mode); bool ast_backup_fw(struct drm_device *dev, u8 *addr, u32 size); diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c index 2aff2e6cf..cfb56ea3a 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -97,6 +97,10 @@ static void ast_detect_config_mode(struct drm_device *dev, u32 *scu_rev)
jregd0 = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd0, 0xff);
jregd1 = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd1, 0xff);
if (!(jregd0 & 0x80) || !(jregd1 & 0x10)) {
+ /* Patch AST2500 */
+ if (((pdev->revision & 0xF0) == 0x40) && ((jregd0 & 0xC0) == 0))
+ ast_patch_ahb_2500(ast);
+
/* Double check it's actually working */
data = ast_read32(ast, 0xf004);
if ((data != 0xFFFFFFFF) && (data != 0x00)) { diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c index 0607658dd..56428798a 100644
--- a/drivers/gpu/drm/ast/ast_post.c
+++ b/drivers/gpu/drm/ast/ast_post.c
@@ -2028,6 +2028,30 @@ static bool ast_dram_init_2500(struct ast_private *ast)
return true;
}

+void ast_patch_ahb_2500(struct ast_private *ast) {
+ u32 data;
+
+ /* Clear bus lock condition */
+ ast_moutdwm(ast, 0x1e600000, 0xAEED1A03);
+ ast_moutdwm(ast, 0x1e600084, 0x00010000);
+ ast_moutdwm(ast, 0x1e600088, 0x00000000);
+ ast_moutdwm(ast, 0x1e6e2000, 0x1688A8A8);
+ data = ast_mindwm(ast, 0x1e6e2070);
+ if (data & 0x08000000) { /* check fast reset */
+
+ ast_moutdwm(ast, 0x1E785004, 0x00000010);
+ ast_moutdwm(ast, 0x1E785008, 0x00004755);
+ ast_moutdwm(ast, 0x1E78500c, 0x00000033);
+ udelay(1000);
+ }
+ do {
+ ast_moutdwm(ast, 0x1e6e2000, 0x1688A8A8);
+ data = ast_mindwm(ast, 0x1e6e2000);
+ } while (data != 1);
+ ast_moutdwm(ast, 0x1e6e207c, 0x08000000); /* clear fast reset */
+}
+
void ast_post_chip_2500(struct drm_device *dev) {
struct ast_private *ast = to_ast_private(dev); @@ -2035,39 +2059,31 @@ void ast_post_chip_2500(struct drm_device *dev)
u8 reg;

reg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd0, 0xff);
- if ((reg & 0x80) == 0) {/* vga only */
+ if ((reg & 0xC0) == 0) {/* vga only */
/* Clear bus lock condition */
- ast_moutdwm(ast, 0x1e600000, 0xAEED1A03);
- ast_moutdwm(ast, 0x1e600084, 0x00010000);
- ast_moutdwm(ast, 0x1e600088, 0x00000000);
- ast_moutdwm(ast, 0x1e6e2000, 0x1688A8A8);
- ast_write32(ast, 0xf004, 0x1e6e0000);
- ast_write32(ast, 0xf000, 0x1);
- ast_write32(ast, 0x12000, 0x1688a8a8);
- while (ast_read32(ast, 0x12000) != 0x1)
- ;
-
- ast_write32(ast, 0x10000, 0xfc600309);
- while (ast_read32(ast, 0x10000) != 0x1)
- ;
+ ast_patch_ahb_2500(ast);
+
+ /* Disable watchdog */
+ ast_moutdwm(ast, 0x1E78502C, 0x00000000);
+ ast_moutdwm(ast, 0x1E78504C, 0x00000000);
+ /* Reset USB port */
+ ast_moutdwm(ast, 0x1E6E2090, 0x20000000);
+ ast_moutdwm(ast, 0x1E6E2094, 0x00004000);
+ if (ast_mindwm(ast, 0x1E6E2070) & 0x00800000) {
+ ast_moutdwm(ast, 0x1E6E207C, 0x00800000);
+ mdelay(100);
+ ast_moutdwm(ast, 0x1E6E2070, 0x00800000);
+ }
+ /* Modify eSPI reset pin */
+ temp = ast_mindwm(ast, 0x1E6E2070);
+ if (temp & 0x02000000)
+ ast_moutdwm(ast, 0x1E6E207C, 0x00004000);

/* Slow down CPU/AHB CLK in VGA only mode */
temp = ast_read32(ast, 0x12008);
temp |= 0x73;
ast_write32(ast, 0x12008, temp);

- /* Reset USB port to patch USB unknown device issue */
- ast_moutdwm(ast, 0x1e6e2090, 0x20000000);
- temp = ast_mindwm(ast, 0x1e6e2094);
- temp |= 0x00004000;
- ast_moutdwm(ast, 0x1e6e2094, temp);
- temp = ast_mindwm(ast, 0x1e6e2070);
- if (temp & 0x00800000) {
- ast_moutdwm(ast, 0x1e6e207c, 0x00800000);
- mdelay(100);
- ast_moutdwm(ast, 0x1e6e2070, 0x00800000);
- }
-
if (!ast_dram_init_2500(ast))
drm_err(dev, "DRAM init failed !\n");

--
2.18.4