On Fri, 2019-03-22 at 13:05 +0800, Hsin-Yi Wang wrote:
On Fri, Mar 22, 2019 at 9:21 AM CK Hu ck.hu@mediatek.com wrote:
Hi, Hsin-yi:
On Thu, 2019-03-21 at 22:09 +0800, Hsin-Yi Wang wrote:
On Thu, Mar 21, 2019 at 9:46 AM CK Hu ck.hu@mediatek.com wrote:
Hi, Hsin-yi:
On Thu, 2019-03-21 at 09:28 +0800, CK Hu wrote:
Hi, Hsin-yi:
On Wed, 2019-03-20 at 15:18 +0800, Hsin-Yi Wang wrote:
mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(), which needs ovl irq for drm_crtc_wait_one_vblank(), since after mtk_dsi_stop() is called, ovl irq will be disabled. If drm_crtc_wait_one_vblank() is called after last irq, it will timeout with this message: "vblank wait timed out on crtc 0". This happens sometimes when turning off the screen.
In drm_atomic_helper.c#disable_outputs(), the calling sequence when turning off the screen is:
- mtk_dsi_encoder_disable() --> mtk_output_dsi_disable() --> mtk_dsi_stop(); // sometimes make vblank timeout in atomic_disable --> mtk_dsi_poweroff();
- mtk_drm_crtc_atomic_disable() --> drm_crtc_wait_one_vblank(); ... --> mtk_dsi_ddp_stop() --> mtk_dsi_poweroff();
mtk_dsi_poweroff() has reference count design, change to make mtk_dsi_stop() called in mtk_dsi_poweroff() when refcount is 0.
Fixes: 0707632b5bac ("drm/mediatek: update DSI sub driver flow for sending commands to panel") Signed-off-by: Hsin-Yi Wang hsinyi@chromium.org
change log: v1->v2:
- update commit message.
- call mtk_dsi_stop() in mtk_dsi_poweroff() when refcount is 0.
drivers/gpu/drm/mediatek/mtk_dsi.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index b00eb2d2e086..e152f37af57d 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -630,6 +630,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi) if (--dsi->refcount != 0) return;
- mtk_dsi_stop(dsi);
- if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) { if (dsi->panel) { if (drm_panel_unprepare(dsi->panel)) {
I think you just move mtk_dsi_stop() into mtk_dsi_poweroff() would works fine, but I would rather like calling mtk_dsi_start() and mtk_dsi_stop() in a symmetric manner. That means you may also move below functions into mtk_dsi_poweron():
mtk_dsi_set_mode(dsi); mtk_dsi_clk_hs_mode(dsi, 1); mtk_dsi_start(dsi);
For MT8183 with bridge panel, calling mtk_dsi_start() in mtk_dsi_poweron() when refcount is 0->1, like the following order, will results in no irq, not sure why though. I think this might be the timing issue you mentioned in patch v1. (MT8183 without bridge panel doesn't have this issue.)
atomic_enable --> mtk_crtc_ddp_hw_init --> mtk_dsi_ddp_start --> mtk_dsi_poweron (ref 0->1) --> drm_panel_prepare --> *mtk_dsi_start // results in no irq for MT8183 with bridge --> drm_crtc_vblank_on
mtk_output_dsi_enable --> mtk_dsi_poweron (ref 1->2, ignored) --> mtk_dsi_start //original position
For mtk_dsi_stop() both with or without bridge is fine.
Add cc Jitao.
Hi Jitao, Do you know if this is a known hardware behavior?
Thanks
mtk_dsi_start must after dsi full setting.
If you put it in mtk_dsi_ddp_start, mtk_dsi_set_mode won't work. DSI will keep cmd mode. So you see no irq.
I think we show keep the mtk_dsi_start in mtk_output_dsi_enable
Best Regards Jitao
I'm not familiar with dsi hardware, so I could not answer why this problem happen. Jitao is familiar with dsi hardware, you may ask him for help. If this is hardware behavior, I could accept asymmetric flow, but please be sure this is hardware behavior not software bug.
Regards, CK
@@ -696,7 +698,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi) } }
mtk_dsi_stop(dsi); mtk_dsi_poweroff(dsi);
dsi->enabled = false;
@@ -1178,6 +1179,8 @@ static int mtk_dsi_remove(struct platform_device *pdev) struct mtk_dsi *dsi = platform_get_drvdata(pdev);
mtk_output_dsi_disable(dsi);
- mtk_dsi_stop(dsi);
- mtk_dsi_poweroff(dsi);
I think mtk_output_dsi_disable() would call mtk_dsi_poweroff(), and mtk_dsi_poweroff() would call mtk_dsi_stop(), so these two line are redundant. And I think you should remove mtk_dsi_stop() in mtk_output_dsi_disable(), why not in this patch?
You've removed mtk_dsi_stop() in mtk_output_dsi_disable(), I just miss it, sorry for this.
Regards, CK
Regards, CK
component_del(&pdev->dev, &mtk_dsi_component_ops); return 0;