Hello Marek, On Mon, 16 Dec 2019 14:54:25 +0100 Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote: > Hi All, > > On 03.12.2019 15:15, Boris Brezillon wrote: > > So that each element in the chain can easily access its predecessor. > > This will be needed to support bus format negotiation between elements > > of the bridge chain. > > > > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> > > Reviewed-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx> > > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > I've noticed that this patch got merged to linux-next as commit > 05193dc38197021894b17239fafbd2eb1afe5a45. Sadly it breaks booting of > Samsung Exynos5250-based Arndale board. Booting stops after following > messages: > > [drm] Exynos DRM: using 14400000.fimd device for DMA mapping operations > exynos-drm exynos-drm: bound 14400000.fimd (ops fimd_component_ops) > exynos-drm exynos-drm: bound 14450000.mixer (ops mixer_component_ops) > exynos-drm exynos-drm: bound 14500000.dsi (ops exynos_dsi_component_ops) > exynos-drm exynos-drm: bound 14530000.hdmi (ops hdmi_component_ops) > [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). > [drm] No driver support for vblank timestamp query. > [drm] Cannot find any crtc or sizes > [drm] Cannot find any crtc or sizes > [drm] Initialized exynos 1.1.0 20180330 for exynos-drm on minor 0 > > I will try to debug this and provide more information soon. > Can you try with this diff applied? --->8--- diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c index 3955f84dc893..118ecedc7621 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c @@ -1523,7 +1523,7 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host, if (out_bridge) { drm_bridge_attach(encoder, out_bridge, NULL); dsi->out_bridge = out_bridge; - list_splice(&encoder->bridge_chain, &dsi->bridge_chain); + list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain); } else { int ret = exynos_dsi_create_connector(encoder); diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index 6c5b80ad6154..e1378d48210f 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -1613,7 +1613,7 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data) * from our driver, since we need to sequence them within the * encoder's enable/disable paths. */ - list_splice(&dsi->encoder->bridge_chain, &dsi->bridge_chain); + list_splice_init(&dsi->encoder->bridge_chain, &dsi->bridge_chain); if (dsi->port == 0) vc4_debugfs_add_regset32(drm, "dsi0_regs", &dsi->regset); @@ -1639,7 +1639,7 @@ static void vc4_dsi_unbind(struct device *dev, struct device *master, * Restore the bridge_chain so the bridge detach procedure can happen * normally. */ - list_splice(&dsi->bridge_chain, &dsi->encoder->bridge_chain); + list_splice_init(&dsi->bridge_chain, &dsi->encoder->bridge_chain); vc4_dsi_encoder_destroy(dsi->encoder); if (dsi->port == 1)