From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:55960 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936041AbeFRIYL (ORCPT ); Mon, 18 Jun 2018 04:24:11 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Anholt , Sean Paul , Boris Brezillon , Sasha Levin Subject: [PATCH 4.16 191/279] drm/vc4: Fix oops dereferencing DPIs connector since panel_bridge. Date: Mon, 18 Jun 2018 10:12:56 +0200 Message-Id: <20180618080616.824872761@linuxfoundation.org> In-Reply-To: <20180618080608.851973560@linuxfoundation.org> References: <20180618080608.851973560@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Anholt [ Upstream commit 164c2416dd40770aba5814f93da835e8a9f7196d ] In the cleanup, I didn't notice that we needed to dereference the connector for the bus_format. Fix the regression by looking up the first (and only) connector attached to us, and assume that its bus_format is what we want. Some day it would be good to have that part of display_info attached to the bridge, instead. v2: Fix stray whitespace change Signed-off-by: Eric Anholt Fixes: 7b1298e05310 ("drm/vc4: Switch DPI to using the panel-bridge helper.") Link: https://patchwork.freedesktop.org/patch/msgid/20180309233256.1667-1-eric@anholt.net Reviewed-by: Sean Paul Reviewed-by: Boris Brezillon Signed-off-by: Sean Paul Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/vc4/vc4_dpi.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/vc4/vc4_dpi.c +++ b/drivers/gpu/drm/vc4/vc4_dpi.c @@ -96,7 +96,6 @@ struct vc4_dpi { struct platform_device *pdev; struct drm_encoder *encoder; - struct drm_connector *connector; void __iomem *regs; @@ -164,14 +163,31 @@ static void vc4_dpi_encoder_disable(stru static void vc4_dpi_encoder_enable(struct drm_encoder *encoder) { + struct drm_device *dev = encoder->dev; struct drm_display_mode *mode = &encoder->crtc->mode; struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder); struct vc4_dpi *dpi = vc4_encoder->dpi; + struct drm_connector_list_iter conn_iter; + struct drm_connector *connector = NULL, *connector_scan; u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE; int ret; - if (dpi->connector->display_info.num_bus_formats) { - u32 bus_format = dpi->connector->display_info.bus_formats[0]; + /* Look up the connector attached to DPI so we can get the + * bus_format. Ideally the bridge would tell us the + * bus_format we want, but it doesn't yet, so assume that it's + * uniform throughout the bridge chain. + */ + drm_connector_list_iter_begin(dev, &conn_iter); + drm_for_each_connector_iter(connector_scan, &conn_iter) { + if (connector_scan->encoder == encoder) { + connector = connector_scan; + break; + } + } + drm_connector_list_iter_end(&conn_iter); + + if (connector && connector->display_info.num_bus_formats) { + u32 bus_format = connector->display_info.bus_formats[0]; switch (bus_format) { case MEDIA_BUS_FMT_RGB888_1X24: @@ -199,6 +215,9 @@ static void vc4_dpi_encoder_enable(struc DRM_ERROR("Unknown media bus format %d\n", bus_format); break; } + } else { + /* Default to 24bit if no connector found. */ + dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT); } if (mode->flags & DRM_MODE_FLAG_NHSYNC)