Re: [PATCH v2 00/26] device link, bridge supplier <-> drm device

From: Peter Rosin
Date: Mon May 07 2018 - 10:09:49 EST

On 2018-05-07 15:56, Daniel Vetter wrote:
> On Fri, May 04, 2018 at 03:51:46PM +0200, Peter Rosin wrote:
>> Hi!
>>
>> It was noted by Russel King [1] that bridges (not using components)
>> might disappear unexpectedly if the owner of the bridge was unbound.
>> Jyri Sarha had previously noted the same thing with panels [2]. Jyri
>> came up with using device links to resolve the panel issue, which
>> was also my (independent) reaction to the note from Russel.
>>
>> This series builds up to the addition of that link in the last
>> patch, but in my opinion the other 25 patches do have merit on their
>> own.
>>
>> The last patch needs testing, while the others look trivial. Jyri, are
>> you able to test? That said, I might have missed some subtlety.
>>
>> Oh and the reason I'm pushing this is of course so that the issue
>> noted by Russel in [1] is addressed which in turn means that the
>> tda998x bridge driver can be patched according to that series without
>> objection (hopefully) and then used from the atmel-hlcdc driver (and
>> other drivers that are not componentized).
>>
>> Changes since v1 https://lkml.org/lkml/2018/4/26/1018
>>
>> - rename .owner to .odev to not get mixed up with the module owner.
>> - added patches for new recent drivers thc63lvd1024 and cdns-dsi
>> - fix for problem in the rockchip_lvds driver reported by 0day
>> - added a WARN in drm_bridge_add if there is no .odev owner device
>>
>> I did *not*:
>> - add any ack from Daniel since he suggested "pdev", and I ended up
>> with "odev" in the rename since I disliked "pdev" about as much
>> as "owner".
>
> As long as it's not owner, I'm fine :-) Ack on the idea still holds.
>
>> - add any port id. The current .of_node (that this series removes)
>> does not identify the port, so that problem seems orthogonal
>> to me.
>
> Hm, from my cursory DT/of code reading last week I thought the port is
> used to lookup the right node, but there's no port thing on the target for
> a phandle? At least that's how current drm_of_find_panel_or_bridge seems
> to work ...

drm_of_find_panel_or_bridge calls of_graph_get_remote_node and that
function looks up the main remote device node, i.e. not the remote
port or endpoint node but the parent node. So, bridges using .of_node
have stored their main device node in the .of_node member. I.e. the
same value as of_node in struct device for all current cases.

Cheers,
Peter

> -Daniel
>>
>> Cheers,
>> Peter
>>
>> [1] https://lkml.org/lkml/2018/4/23/769
>> [2] https://www.spinics.net/lists/dri-devel/msg174275.html
>>
>> Peter Rosin (26):
>> drm/bridge: allow optionally specifying an owner .odev device
>> drm/bridge: adv7511: provide an owner .odev device
>> drm/bridge/analogix: core: specify the owner .odev of the bridge
>> drm/bridge: analogix-anx78xx: provide an owner .odev device
>> drm/bridge: cdns-dsi: provide an owner .odev device
>> drm/bridge: vga-dac: provide an owner .odev device
>> drm/bridge: lvds-encoder: provide an owner .odev device
>> drm/bridge: megachips-stdpxxxx-ge-b850v3-fw: provide an owner .odev
>> device
>> drm/bridge: nxp-ptn3460: provide an owner .odev device
>> drm/bridge: panel: provide an owner .odev device
>> drm/bridge: ps8622: provide an owner .odev device
>> drm/bridge: sii902x: provide an owner .odev device
>> drm/bridge: sii9234: provide an owner .odev device
>> drm/bridge: sii8620: provide an owner .odev device
>> drm/bridge: synopsys: provide an owner .odev device for the bridges
>> drm/bridge: tc358767: provide an owner .odev device
>> drm/bridge: thc63lvd1024: provide an owner .odev device
>> drm/bridge: ti-tfp410: provide an owner .odev device
>> drm/exynos: mic: provide an owner .odev device for the bridge
>> drm/mediatek: hdmi: provide an owner .odev device for the bridge
>> drm/msm: specify the owner .odev of the bridges
>> drm/rcar-du: lvds: provide an owner .odev device for the bridge
>> drm/sti: provide an owner .odev device for the bridges
>> drm/bridge: remove the .of_node member
>> drm/bridge: require the owner .odev to be filled in on
>> drm_bridge_add/attach
>> drm/bridge: establish a link between the bridge supplier and consumer
>>
>> drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 2 +-
>> drivers/gpu/drm/bridge/analogix-anx78xx.c | 5 +----
>> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 1 +
>> drivers/gpu/drm/bridge/cdns-dsi.c | 2 +-
>> drivers/gpu/drm/bridge/dumb-vga-dac.c | 2 +-
>> drivers/gpu/drm/bridge/lvds-encoder.c | 2 +-
>> .../drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 2 +-
>> drivers/gpu/drm/bridge/nxp-ptn3460.c | 2 +-
>> drivers/gpu/drm/bridge/panel.c | 4 +---
>> drivers/gpu/drm/bridge/parade-ps8622.c | 2 +-
>> drivers/gpu/drm/bridge/sii902x.c | 2 +-
>> drivers/gpu/drm/bridge/sii9234.c | 2 +-
>> drivers/gpu/drm/bridge/sil-sii8620.c | 2 +-
>> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 4 +---
>> drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 4 +---
>> drivers/gpu/drm/bridge/tc358767.c | 2 +-
>> drivers/gpu/drm/bridge/thc63lvd1024.c | 2 +-
>> drivers/gpu/drm/bridge/ti-tfp410.c | 2 +-
>> drivers/gpu/drm/drm_bridge.c | 26 +++++++++++++++++++++-
>> drivers/gpu/drm/exynos/exynos_drm_mic.c | 2 +-
>> drivers/gpu/drm/mediatek/mtk_hdmi.c | 2 +-
>> drivers/gpu/drm/msm/dsi/dsi_manager.c | 1 +
>> drivers/gpu/drm/msm/edp/edp_bridge.c | 1 +
>> drivers/gpu/drm/msm/hdmi/hdmi_bridge.c | 1 +
>> drivers/gpu/drm/rcar-du/rcar_lvds.c | 2 +-
>> drivers/gpu/drm/rockchip/rockchip_lvds.c | 2 +-
>> drivers/gpu/drm/sti/sti_dvo.c | 2 +-
>> drivers/gpu/drm/sti/sti_hda.c | 1 +
>> drivers/gpu/drm/sti/sti_hdmi.c | 1 +
>> include/drm/drm_bridge.h | 8 +++----
>> 30 files changed, 57 insertions(+), 36 deletions(-)
>>
>> --
>> 2.11.0
>>
>