[PATCH v15 00/16] drm: Add Samsung MIPI DSIM bridge
Marek Szyprowski
m.szyprowski at samsung.com
Tue Mar 7 10:44:22 UTC 2023
Hello,
On 07.03.2023 10:22, Jagan Teki wrote:
> On Tue, Mar 7, 2023 at 1:25 PM Jagan Teki <jagan at amarulasolutions.com> wrote:
>> On Tue, Mar 7, 2023 at 4:11 AM Marek Szyprowski
>> <m.szyprowski at samsung.com> wrote:
>>> On 06.03.2023 18:24, Jagan Teki wrote:
>>>> On Mon, Mar 6, 2023 at 4:32 PM Marek Szyprowski
>>>> <m.szyprowski at samsung.com> wrote:
>>>>> On 04.03.2023 19:59, Jagan Teki wrote:
>>>>>> On Sat, Mar 4, 2023 at 3:56 AM Marek Szyprowski
>>>>>> <m.szyprowski at samsung.com> wrote:
>>>>>>> On 03.03.2023 15:51, Jagan Teki wrote:
>>>>>>>> This series supports common bridge support for Samsung MIPI DSIM
>>>>>>>> which is used in Exynos and i.MX8MM SoC's.
>>>>>>>>
>>>>>>>> The final bridge supports both the Exynos and i.MX8M Mini/Nano/Plus.
>>>>>>>>
>>>>>>>> Inki Dae: please note that this series added on top of exynos-drm-next
>>>>>>>> since few exynos dsi changes are not been part of drm-misc-next.
>>>>>>>> Request you to pick these via exynos-drm-next, or let me know if you
>>>>>>>> have any comments?
>>>>>>> I gave it a try on Exynos TM2e and unfortunately it nukes again:
>>>>>>>
>>>>>>> exynos-drm exynos-drm: bound 13970000.hdmi (ops hdmi_component_ops)
>>>>>>> Unable to handle kernel paging request at virtual address 003d454d414e5675
>>>>>>> ...
>>>>>>> [003d454d414e5675] address between user and kernel address ranges
>>>>>>> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
>>>>>>> Modules linked in:
>>>>>>> CPU: 4 PID: 9 Comm: kworker/u16:0 Not tainted 6.2.0-next-20230303+ #13341
>>>>>>> Hardware name: Samsung TM2E board (DT)
>>>>>>> Workqueue: events_unbound deferred_probe_work_func
>>>>>>> pstate: 000000c5 (nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>>>>> pc : drm_connector_list_iter_next+0x58/0x100
>>>>>>> lr : drm_connector_list_iter_next+0x2c/0x100
>>>>>>> sp : ffff80000bbab910
>>>>>>> ...
>>>>>>> Call trace:
>>>>>>> drm_connector_list_iter_next+0x58/0x100
>>>>>>> drm_mode_config_reset+0xfc/0x144
>>>>>>> exynos_drm_bind+0x160/0x1b8
>>>>>>> try_to_bring_up_aggregate_device+0x168/0x1d4
>>>>>>> __component_add+0xa8/0x170
>>>>>>> component_add+0x14/0x20
>>>>>>> hdmi_probe+0x3fc/0x6d4
>>>>>>> platform_probe+0x68/0xd8
>>>>>>> really_probe+0x148/0x2b4
>>>>>>> __driver_probe_device+0x78/0xe0
>>>>>>> driver_probe_device+0xd8/0x160
>>>>>>> __device_attach_driver+0xb8/0x138
>>>>>>> bus_for_each_drv+0x84/0xe0
>>>>>>> __device_attach+0xa8/0x1b0
>>>>>>> device_initial_probe+0x14/0x20
>>>>>>> bus_probe_device+0xb0/0xb4
>>>>>>> deferred_probe_work_func+0x8c/0xc8
>>>>>>> process_one_work+0x288/0x6c8
>>>>>>> worker_thread+0x24c/0x450
>>>>>>> kthread+0x118/0x11c
>>>>>>> ret_from_fork+0x10/0x20
>>>>>> This looks not related to dsi to me since there is no exynos_drm_dsi
>>>>>> call in the trace. look hdmi related. Moreover, I think the exynos dsi
>>>>>> worked well on v10 and I couldn't find any potential differences in
>>>>>> terms of call flow change.
>>>>>> https://gitlab.com/openedev/kernel/-/commits/imx8mm-dsi-v10
>>>>> Well, the issue is definitely related to this patchset. On Friday, due
>>>>> to other kernel messages, I missed the most important part of the log:
>>>>>
>>>>> [drm] Exynos DRM: using 13800000.decon device for DMA mapping operations
>>>>> exynos-drm exynos-drm: bound 13800000.decon (ops decon_component_ops)
>>>>> exynos-drm exynos-drm: bound 13880000.decon (ops decon_component_ops)
>>>>> exynos-dsi 13900000.dsi: [drm:samsung_dsim_host_attach] Attached s6e3hf2
>>>>> device
>>>>> exynos-dsi 13900000.dsi: request interrupt failed with -22
>>>>> panel-samsung-s6e3ha2: probe of 13900000.dsi.0 failed with error -22
>>>>> exynos-drm exynos-drm: bound 13900000.dsi (ops exynos_dsi_component_ops)
>>>>> exynos-drm exynos-drm: bound 13930000.mic (ops exynos_mic_component_ops)
>>>>>
>>>>> It looks that the are at least 2 issues. The first one related to TE
>>>>> interrupt registration, the second is broken error path, which should
>>>>> free allocated resources and stop DRM from binding/initialization.
>>>>>
>>>>> This patch fixes the issue (TE gpio/interrupt is optional!):
>>>>>
>>>>> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c
>>>>> b/drivers/gpu/drm/bridge/samsung-dsim.c
>>>>> index b4a5348b763c..ed83495fe105 100644
>>>>> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
>>>>> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
>>>>> @@ -1518,7 +1518,9 @@ static int samsung_dsim_register_te_irq(struct
>>>>> samsung_dsim *dsi, struct device
>>>>> int ret;
>>>>>
>>>>> dsi->te_gpio = devm_gpiod_get_optional(dev, "te", GPIOD_IN);
>>>>> - if (IS_ERR(dsi->te_gpio))
>>>>> + if (!dsi->te_gpio)
>>>>> + return 0;
>>>>> + else if (IS_ERR(dsi->te_gpio))
>>>> I think I missed this change from v10 where Marek V commented to move
>>>> this in dsim instead of in Exynos. anyway, I will correct this.
>>>>
>>>>> return dev_err_probe(dev, PTR_ERR(dsi->te_gpio),
>>>>> "failed to get te GPIO\n");
>>>>>
>>>>> te_gpio_irq = gpiod_to_irq(dsi->te_gpio);
>>>>>
>>>>>
>>>>> The error path in samsung_dsim_host_attach() after
>>>>> samsung_dsim_register_te_irq() failure is wrong. It lacks cleaning up
>>>>> the allocated resources (removing the bridge, detaing the dsi device).
>>>> This is because of the same discussion of moving TE GPIO in dsim instead exynos.
>>> Well, I'm not very happy about adding more and more features/changes to
>>> this single patch. I think that once we got the first version that was
>>> working on both Exynos and IMX, all other changes should be done
>>> incrementally to avoid this kind of issues...
>> This is what I thought too, v10 was that ready to merge patchset.
>> Since it was delayed it is obvious to have more comments from other
>> developers in the community. This is what happened with the TE GPIO
>> change.
>>
>>>
>>>> How about register TE GPIO before calling host attach like this,
>>>>
>>>> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
>>>> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
>>>> @@ -1598,9 +1598,6 @@ static int samsung_dsim_host_attach(struct
>>>> mipi_dsi_host *host,
>>>>
>>>> drm_bridge_add(&dsi->bridge);
>>>>
>>>> - if (pdata->host_ops && pdata->host_ops->attach)
>>>> - pdata->host_ops->attach(dsi, device);
>>>> -
>>>> /*
>>>> * This is a temporary solution and should be made by more generic way.
>>>> *
>>>> @@ -1613,6 +1610,9 @@ static int samsung_dsim_host_attach(struct
>>>> mipi_dsi_host *host,
>>>> return ret;
>>>> }
>>>>
>>>> + if (pdata->host_ops && pdata->host_ops->attach)
>>>> + pdata->host_ops->attach(dsi, device);
>>>> +
>>>> dsi->lanes = device->lanes;
>>>> dsi->format = device->format;
>>>> dsi->mode_flags = device->mode_flags;
>>>>
>>>> Would you please check this?
>>> Yes. This fixes the error path.
>> Okay. I'm sending v16 with the above two changes.
> Would you please test this v16 for confirmation before sending it to
> the mailing list?
v16 works fine here. Feel free to add:
Tested-by: Marek Szyprowski <m.szyprowski at samsung.com>
to the Exynos related patches (if there is still no such tag yet).
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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