Hi Andrzej,
Thank you for the comments.
On 04/23/2014 04:37 PM, Andrzej Hajda wrote:
On 04/23/2014 05:45 AM, YoungJun Cho wrote:
Hi again Andrzej,
On 04/23/2014 10:01 AM, YoungJun Cho wrote:
Hi Andrzej
Thank you for comments.
On 04/22/2014 09:15 PM, Andrzej Hajda wrote:
Hi YoungJun,
On 04/21/2014 02:28 PM, YoungJun Cho wrote:
Some phy control registers are not kept after software reset.
So this patch makes the clocks containing phy control to be set
after software reset.
Signed-off-by: YoungJun Cho <yj44....@samsung.com>
Acked-by: Inki Dae <inki....@samsung.com>
Acked-by: Kyungmin Park <kyungmin.p...@samsung.com>
---
drivers/gpu/drm/exynos/exynos_drm_dsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index 956e5f3..2cf1f0b 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -946,10 +946,10 @@ static irqreturn_t exynos_dsi_irq(int irq, void
*dev_id)
static int exynos_dsi_init(struct exynos_dsi *dsi)
{
- exynos_dsi_enable_clock(dsi);
exynos_dsi_reset(dsi);
enable_irq(dsi->irq);
exynos_dsi_wait_for_reset(dsi);
+ exynos_dsi_enable_clock(dsi);
exynos_dsi_init_link(dsi);
return 0;
I have commented it in the previous version of the patchset. I repeat it
again.
This is a regression, on exynos4210-trats I have 'timeout waiting for
reset' message after dpms off, on.
I'm really sorry for that. I misunderstood last time.
I think the original codes were correct, because the reset timeout would
be occurred without clock activation.
This is not true.
I'll check and fix again.
(By the way, why am I ok?)
I have not verified with exynos4210-trats board yet(I have to get it),
but reset timeout is occured in exynos_dsi_wait_for_reset()
with &dsi->completed and that is completed by exynos_dsi_irq().
And the regulators and clocks are enabled by exynos_dsi_poweron(),
NOT by exynos_dsi_enable_clock().
So I think the reset timeout is not related with this patch.
As far as I remember there were at least two issues with init sequence:
- spurious irq storm after power on and before reset,
- irq reset timeouts after reset and without enabled clock.
The current sequence is a result of tests on live hw (documentation were
not helpful in this case). I think it could be improved little bit more
by moving exynos_dsi_enable_clock just after enable_irq this will
eliminate possible timeout when RST_RELEASE irq is signaled but irq is
still disabled. The sequence should look like below:
exynos_dsi_reset(dsi);
enable_irq(dsi->irq);
exynos_dsi_enable_clock(dsi);
exynos_dsi_wait_for_reset(dsi);
exynos_dsi_init_link(dsi);
And PHY related configuration could be put somewhere after
exynos_dsi_wait_for_reset.
I have tested this sequence on trats, it seems to be OK.
It also works well in Exynos5420 target.
I think it would be better to remove this patch and implement new PHY
control functions with this modification.
Thank you.
Best regards YJ
Regards
Andrzej
Anyway I need more investigation.
Thank you.
Best regards YJ
I will comment your previous answer here to make the discussion easier:
As I mentioned in description, it came from phy control registers.
Fortunately Exynos4 SoCs are safe, but the DSIM_PHYCTRL_REG,
DSIM_PHYTIMING_REG, DSIM_PHYTIMING1_REG and DSIM_PHYTIMING2_REG are
affected which are used in exynos_dsi_set_pll() for Exynos5 SoCs.
So this patch is required for Exynos5 SoCs.
In the moment this patch is applied exynos_dsi_set_pll do not touch phy
registers you have mentioned.
Your change would be more clear if it will be merged together with the
patch adding PHYCTRL settings.
Anyway, solution is simple - please set PHY registers after reset and
configure clocks before reset to avoid
reset timeouts, is there any reason to not do it this way?
The only reason is that the PHY control is related with PLL control and
that was in exynos_dsi_enable_clock() call path.
So I just wanted to keep current sequence.
If there is no way to use previous one, I'll consider your approach.
Thank you.
Best regards YJ
Regards
Andrzej
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