Re: [PATCH] drm/rockchip: vop: power off until vop standby take effect
From: Mark yao
Date: Tue Feb 03 2015 - 22:56:39 EST
On 2015å02æ04æ 11:48, Daniel Kurtz wrote:
On Feb 4, 2015 11:38 AM, "Mark yao" <mark.yao@xxxxxxxxxxxxxx> wrote:
On 2015å02æ02æ 15:53, Daniel Vetter wrote:
On Mon, Feb 02, 2015 at 10:30:09AM +0800, Mark yao wrote:
On 2015å02æ02æ 10:07, Daniel Kurtz wrote:
Hi Mark, Heiko,
On Sat, Jan 31, 2015 at 4:41 PM, Mark Yao <mark.yao@xxxxxxxxxxxxxx> wrote:
Vop standby will take effect end of current frame,
if dsp_hold_valid_irq happen, it means vop standby complete.
we must wait standby complete when we want to disable aclk,
if not, memory bus maybe dead.
Signed-off-by: Mark Yao <mark.yao@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 76 ++++++++++++++++++++++-----
1 file changed, 63 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index fb25836..47ea61f 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -89,6 +89,7 @@ struct vop {
/* mutex vsync_ work */
struct mutex vsync_mutex;
bool vsync_work_pending;
+ struct completion dsp_hold_completion;
const struct vop_data *data;
@@ -382,6 +383,34 @@ static bool is_alpha_support(uint32_t format)
}
}
+static void vop_dsp_hold_valid_irq_enable(struct vop *vop)
+{
+ unsigned long flags;
+
+ BUG_ON(!vop->is_enabled);
Re: Heiko "use a WARN_ON":
If the VOP clock is off, then the system will just hang when trying to
write the VOP register so in this case, BUG_ON gives a more reliable
crash dump than the hang.
In this way, you are right, if vop clocks is disabled, write vop register
will hang system, and the WARN_ON
if (WARN_ON(cond))
return;
is what we commonly use in i915. Because it's really not any good to use
BUG_ON in drm drivers, at least if you expect anyone to use fbcon on top
of it (i.e. anything even remotely resembling a normal distro): Then the
intial modeset is all done under console_lock, which means that _none_ of
your BUG_ON will ever get out over serial console.
The problem is fbcon locking, but no fool yet signed up to fix it (it's
horrible, I looked ...).
-Daniel
I know this problem, if fbcon locking, and BUG_ON, we can't get any log from serial console, Trouble
me many times. So know, if no drm log output, the first thing I do is remove the fbcon lock, and then
we can see the crash dump.
But here, I expect to use BUG_ON, because if BUG happen, vop register will hang system, and WARN_ON
may be have no chance to output.
Yeah, but danvet is suggesting we just return immediately on the
WARN_ON condition, to avoid accessing the vop registers and hanging.
Thus, the WARN_ON will have a chance to put out (unless the early
return path goes off and finds some other unprotected path goes to
access unlocked registers).
-Dan
All right, I got it.
Mark
--
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Rockchip çåçèåçåæéåå
Fuzhou Headquarters
Addr:No.21 Building, A District, Fuzhou
Software Park, 89 Soft Avenue, Tongpan Road,
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E-mail:mark.yao@xxxxxxxxxxxxxx
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