Hello Krzysztof,

On 05/25/2016 03:48 AM, Krzysztof Kozlowski wrote:

On 05/24/2016 07:41 PM, Javier Martinez Canillas wrote:

quoted

The MFC IP is also inter-connected by an Async-Bridge so the CLK_ACLK333
has to be ungated during a power domain switch. Trying to do it when the
clock is gated will fail and lead to an imprecise external abort error
when the driver tries to access the MFC registers with the PD disabled.

For example, if the s5p-mfc module is removed and the MFC PD turned off:

[  186.835606] Power domain power-domain at 10044060 disable failed
[  186.835671] s5p-mfc 11000000.codec: Removing 11000000.codec
[  186.837670] Power domain power-domain at 10044060 disable failed

And when the module is inserted again:

[ 2395.176956] s5p_mfc_wait_for_done_dev:34: Interrupt (dev->int_type:0, command:12) timed out
[ 2395.177031] s5p_mfc_init_hw:272: Failed to load firmware
[ 2395.177384] Unhandled fault: imprecise external abort (0x1406) at 0x00000000
[ 2395.177441] pgd = ec3b4000
[ 2395.177467] [00000000] *pgd=00000000
[ 2395.177507] Internal error: : 1406 [#1] PREEMPT SMP ARM
[ 2395.177550] Modules linked in: s5p_mfc mwifiex_sdio mwifiex uvcvideo s5p_jpeg v4l2_mem2mem videobuf2_vmalloc videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media [last unloaded: s5p_mfc]
[ 2395.177774] CPU: 1 PID: 2382 Comm: v4l_id Tainted: G        W       4.6.0-rc6-next-20160502-00010-g7730dc64d2c1-dirty #179
[ 2395.177857] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 2395.177906] task: ed275500 ti: e6c8c000 task.ti: e6c8c000
[ 2395.177996] PC is at s5p_mfc_reset+0x1c4/0x284 [s5p_mfc]
[ 2395.178057] LR is at s5p_mfc_reset+0x1a4/0x284 [s5p_mfc]

This patch fixes this issue by adding the CLK_ACLK333 as an Async-Bridge
clock for the MFC power domain, so the PD configuration works properly.

Signed-off-by: Javier Martinez Canillas <redacted>

---

 arch/arm/boot/dts/exynos5420.dtsi | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Indeed patch #1 is not a hard dependency here because there are no other
asb clocks. It is entirely obvious but works fine.

You are right, the reason why is not a hard dependency is because it fails
anyways so this patch (which will make it fail due the clock being missed)
won't have any effect.
 

Reviewed-by: Krzysztof Kozlowski <redacted>

Thanks!

Unless all other patches are meant to current fixes cycle (and/or
cc-stable), I do not plan to apply it now. I'll take it for v4.8, because:
1. Your previous patches are needed. Without them bind/unbind won't work.
2. This is not reproducible in a regular driver operation.
3. It needs clock change to actually be useful.

Is it okay?

Agreed, that's also why I didn't cc stable on this series.
 

Best regards,
Krzysztof

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America