On 10.11.21 05:11, Irui Wang wrote:
Hi, Dafna,
Thanks for the patch.
On Tue, 2021-11-09 at 10:46 +0200, Dafna Hirschfeld wrote:
On 03.11.21 13:04, Dafna Hirschfeld wrote:
On 03.11.21 10:19, Irui Wang wrote:
Hi,
The "len" of share_buf copied should be always 8 alignment;
do you have other logs to prove the len is not 8 alignment when
errors
appear?
Hi, I found out that "sizeof(mdp_ipi_comm) = 20"
this is due to the macro #pragma pack(push, 4) in mtk_mdp_ipi.h
see [1]
[1] http://lkml.iu.edu/hypermail/linux/kernel/2109.2/04978.html
Hi Irui Wang,
Any update regarding that patch?
Can you give more explanation for that errors that we see
when the buffer size is not a multiple of 8?
Thanks,
Dafna
share_buf is a mapped memory by ioremap, it should be better use
memcpy_to/fromio instead of memcpy because of alignment.
As for memcpy_toio, it may also have requirements for alignment, we can
also get such information from:
https://elixir.bootlin.com/linux/v5.15/source/drivers/mtd/spi-nor/controllers/aspeed-smc.c#L207
.
So, it's not VPU HW bug or limitation, it's memcpy_toio requirements,
maybe we can modify IPI message to do alignment, but it need modify
both kernel and vpu firmware, which will break upstream backward
compatible, we think it's unacceptale.
If this patch can solve the issue, we think it's OK.
In such case shouldn't we also make sure that the address of
send_obj->share_buf is 8 aligend before calling memcpy_toio,
and also shouldn't we make the same checks for the memcpy_fromio ?
Thanks,
Dafna
Thanks
Thanks,
Dafna
[58.350841] mtk-mdp 14001000.rdma: processing failed: -22
On Wed, 2021-11-03 at 16:03 +0800, houlong wei wrote:
Add mtk-vpu driver expert irui.wang in the loop.
On Mon, 2021-10-18 at 15:07 +0800, Dafna Hirschfeld wrote:
On 18.10.21 03:16, Alexandre Courbot wrote:
Hi Hans!
On Mon, Oct 4, 2021 at 6:37 PM Hans Verkuil <
hverkuil@xxxxxxxxx>
wrote:
On 20/09/2021 19:04, Dafna Hirschfeld wrote:
From: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
When running memcpy_toio:
memcpy_toio(send_obj->share_buf, buf, len);
it was found that errors appear if len is not a
multiple of
8:
[58.350841] mtk-mdp 14001000.rdma: processing failed:
-22
Why do errors appear? Is that due to a HW bug? Some other
reason?
MTK folks would be the best placed to answer this, but
since the
failure is reported by the firmware I'd suspect either a
firmware
or
hardware limitation.
This patch ensures the copy of a multiple of 8 size by
calling
round_up(len, 8) when copying
Fixes: e6599adfad30 ("media: mtk-vpu: avoid unaligned
access
to
DTCM buffer.")
Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx
Signed-off-by: Enric Balletbo i Serra <
enric.balletbo@xxxxxxxxxxxxx>
Signed-off-by: Dafna Hirschfeld <
dafna.hirschfeld@xxxxxxxxxxxxx
Reviewed-by: Houlong Wei <houlong.wei@xxxxxxxxxxxx>
---
changes since v3:
1. multile -> multiple
2. add inline doc
changes since v2:
1. do the extra copy only if len is not multiple of 8
changes since v1:
1. change sign-off-by tags
2. change values to memset
drivers/media/platform/mtk-vpu/mtk_vpu.c | 15
++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/media/platform/mtk-vpu/mtk_vpu.c
b/drivers/media/platform/mtk-vpu/mtk_vpu.c
index ec290dde59cf..1df031716c8f 100644
--- a/drivers/media/platform/mtk-vpu/mtk_vpu.c
+++ b/drivers/media/platform/mtk-vpu/mtk_vpu.c
@@ -349,7 +349,20 @@ int vpu_ipi_send(struct
platform_device
*pdev,
}
} while (vpu_cfg_readl(vpu, HOST_TO_VPU));
- memcpy_toio(send_obj->share_buf, buf, len);
+ /*
+ * when copying data to the vpu hardware, the
memcpy_toio
operation must copy
+ * a multiple of 8. Otherwise the processing
fails
Same here: it needs to explain why the processing fails.
Is writing 'due to hardware or firmware limitation' enough?
If not, then we should wait for mediatek people's response to
explain
if they know more
+ */
+ if (len % 8 != 0) {
+ unsigned char data[SHARE_BUF_SIZE];
Wouldn't it be more robust if you say:
unsigned char data[sizeof(send_obj-
share_buf)];
Definitely yes.
I'll send v5 fixing this
I also think that the SHARE_BUF_SIZE define needs a
comment
stating that it must be a
multiple of 8, otherwise unexpected things can happen.
You also noticed that the current SHARE_BUF_SIZE define
is too
low, but I saw
no patch correcting this. Shouldn't that be fixed as
well?
AFAICT the firmware expects this exact size on its end, so
I
don't
believe it can be changed that easily. But maybe someone
from MTK
can
prove me wrong.
I looked further and noted that the structs that are larger
than
'SHARE_BUF_SIZE'
(venc_ap_ipi_msg_enc_ext venc_ap_ipi_msg_set_param_ext)
are used by drivers that don't use this vpu api, so actually
SHARE_BUF_SIZE is
not too low and as Corurbot worte probably not changeable.
Thanks,
Dafna
Cheers,
Alex.
