From: Marek Szyprowski <m.szyprowski@samsung.com>
To: Alex Deucher <alexdeucher@gmail.com>
Cc: "Christian König" <christian.koenig@amd.com>,
"Shane Francis" <bigbeeshane@gmail.com>,
"Maling list - DRI developers" <dri-devel@lists.freedesktop.org>,
"Dave Airlie" <airlied@linux.ie>,
"Deucher, Alexander" <alexander.deucher@amd.com>,
LKML <linux-kernel@vger.kernel.org>,
amd-gfx-request@lists.freedesktop.org
Subject: Re: [v4,1/3] drm/prime: use dma length macro when mapping sg
Date: Tue, 31 Mar 2020 16:29:09 +0200 [thread overview]
Message-ID: <b65eddc1-e88a-cd64-86bb-5a9e99a7671d@samsung.com> (raw)
In-Reply-To: <CADnq5_NEhfZwE6B0UBu0My7Sk5YNoDE=7Nj_CUYpPe9HOjpjqQ@mail.gmail.com>
Hi Alex,
On 2020-03-31 16:10, Alex Deucher wrote:
> On Tue, Mar 31, 2020 at 1:25 AM Marek Szyprowski
> <m.szyprowski@samsung.com> wrote:
>> Hi Alex,
>>
>> On 2020-03-30 15:23, Alex Deucher wrote:
>>> On Mon, Mar 30, 2020 at 4:18 AM Marek Szyprowski
>>> <m.szyprowski@samsung.com> wrote:
>>>> Hi
>>>>
>>>> On 2020-03-27 10:10, Marek Szyprowski wrote:
>>>>> Hi Christian,
>>>>>
>>>>> On 2020-03-27 09:11, Christian König wrote:
>>>>>> Am 27.03.20 um 08:54 schrieb Marek Szyprowski:
>>>>>>> On 2020-03-25 10:07, Shane Francis wrote:
>>>>>>>> As dma_map_sg can reorganize scatter-gather lists in a
>>>>>>>> way that can cause some later segments to be empty we should
>>>>>>>> always use the sg_dma_len macro to fetch the actual length.
>>>>>>>>
>>>>>>>> This could now be 0 and not need to be mapped to a page or
>>>>>>>> address array
>>>>>>>>
>>>>>>>> Signed-off-by: Shane Francis <bigbeeshane@gmail.com>
>>>>>>>> Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
>>>>>>> This patch landed in linux-next 20200326 and it causes a kernel
>>>>>>> panic on
>>>>>>> various Exynos SoC based boards.
>>>>>>>> ---
>>>>>>>> drivers/gpu/drm/drm_prime.c | 2 +-
>>>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
>>>>>>>> index 86d9b0e45c8c..1de2cde2277c 100644
>>>>>>>> --- a/drivers/gpu/drm/drm_prime.c
>>>>>>>> +++ b/drivers/gpu/drm/drm_prime.c
>>>>>>>> @@ -967,7 +967,7 @@ int drm_prime_sg_to_page_addr_arrays(struct
>>>>>>>> sg_table *sgt, struct page **pages,
>>>>>>>> index = 0;
>>>>>>>> for_each_sg(sgt->sgl, sg, sgt->nents, count) {
>>>>>>>> - len = sg->length;
>>>>>>>> + len = sg_dma_len(sg);
>>>>>>>> page = sg_page(sg);
>>>>>>>> addr = sg_dma_address(sg);
>>>>>>> Sorry, but this code is wrong :(
>>>>>> Well it is at least better than before because it makes most drivers
>>>>>> work correctly again.
>>>>> Well, I'm not sure that a half-broken fix should be considered as a
>>>>> fix ;)
>>>>>
>>>>> Anyway, I just got the comment from Shane, that my patch is fixing the
>>>>> issues with amdgpu and radeon, while still working fine for exynos, so
>>>>> it is indeed a proper fix.
>>>> Today I've noticed that this patch went to final v5.6 without even a day
>>>> of testing in linux-next, so v5.6 is broken on Exynos and probably a few
>>>> other ARM archs, which rely on the drm_prime_sg_to_page_addr_arrays
>>>> function.
>>> Please commit your patch and cc stable.
>> I've already did that: https%3A%2F%2Flkml.org%2Flkml%2F2020%2F3%2F27%2F555
> Do you have drm-misc commit rights or do you need someone to commit
> this for you?
I have no access to drm-misc.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
next prev parent reply other threads:[~2020-03-31 14:29 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-25 9:07 [PATCH v4 0/3] AMDGPU / RADEON / DRM Fix mapping of user pages Shane Francis
2020-03-25 9:07 ` [PATCH v4 1/3] drm/prime: use dma length macro when mapping sg Shane Francis
2020-03-25 13:56 ` Ruhl, Michael J
[not found] ` <CGME20200327075458eucas1p2f1011560c5d2d2a754d2394f56367ebb@eucas1p2.samsung.com>
2020-03-27 7:54 ` [v4,1/3] " Marek Szyprowski
2020-03-27 8:11 ` Christian König
2020-03-27 9:10 ` Marek Szyprowski
2020-03-30 8:18 ` Marek Szyprowski
2020-03-30 9:39 ` Shane Francis
2020-03-30 12:32 ` Shane Francis
2020-03-30 12:34 ` Shane Francis
2020-03-30 13:23 ` Alex Deucher
2020-03-31 5:25 ` Marek Szyprowski
2020-03-31 14:10 ` Alex Deucher
2020-03-31 14:29 ` Marek Szyprowski [this message]
[not found] ` <CGME20200327082702eucas1p1a66dd059480c9d02b8f0f3ab225db2c3@eucas1p1.samsung.com>
2020-03-27 8:26 ` Marek Szyprowski
2020-03-25 9:07 ` [PATCH v4 2/3] drm/amdgpu: fix scatter-gather mapping with user pages Shane Francis
2020-03-25 14:00 ` Ruhl, Michael J
2020-03-25 9:07 ` [PATCH v4 3/3] drm/radeon: " Shane Francis
2020-03-25 14:19 ` Ruhl, Michael J
2020-03-25 15:54 ` Shane Francis
2020-03-25 16:08 ` Alex Deucher
2020-03-25 13:11 ` [PATCH v4 0/3] AMDGPU / RADEON / DRM Fix mapping of " Ruhl, Michael J
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