* [PATCH V4] drm/stm: Fix bus_flags handling
@ 2021-01-27 11:07 Marek Vasut
2021-01-28 13:55 ` yannick Fertre
2021-02-15 17:43 ` Philippe CORNU
0 siblings, 2 replies; 3+ messages in thread
From: Marek Vasut @ 2021-01-27 11:07 UTC (permalink / raw)
To: dri-devel
Cc: Marek Vasut, Benjamin Gaignard, Antonio Borneo, Vincent Abriou,
Philippe Cornu, Yannick Fertre, Maxime Coquelin, Sam Ravnborg,
linux-stm32, linux-arm-kernel, Alexandre Torgue
The drm_display_mode_to_videomode() does not populate DISPLAY_FLAGS_DE_LOW
or DISPLAY_FLAGS_PIXDATA_NEGEDGE flags in struct videomode. Therefore, no
matter what polarity the next bridge or display might require, these flags
are never set, and thus the LTDC GCR_DEPOL and GCR_PCPOL bits are never set,
and the LTDC behaves as if both DISPLAY_FLAGS_PIXDATA_POSEDGE and
DISPLAY_FLAGS_DE_HIGH were always set.
The fix for this problem is taken almost verbatim from MXSFB driver. In
case there is a bridge attached to the LTDC, the bridge might have extra
polarity requirements, so extract bus_flags from the bridge and use them
for LTDC configuration. Otherwise, extract bus_flags from the connector,
which is the display.
Fixes: b759012c5fa7 ("drm/stm: Add STM32 LTDC driver")
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Antonio Borneo <antonio.borneo@st.com>
Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Philippe Cornu <philippe.cornu@st.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Yannick Fertre <yannick.fertre@st.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: dri-devel@lists.freedesktop.org
---
V2: Check if ldev->bridge->timings is non-NULL before accessing it
V3: get bus_flags from connector (from Yannick)
- Display controller could support several connectors (not connected at
the same time). ie: stm32mp15c-DK2 board have 2 connectors (HDMI + DSI).
Driver check which connector is connected to get the bus flag.
V4: get bridge from encoder (from Yannick)
---
drivers/gpu/drm/stm/ltdc.c | 33 +++++++++++++++++++++++++++++++--
1 file changed, 31 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 6e28e6b60e72..acc9f6694eb6 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -544,13 +544,42 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
struct ltdc_device *ldev = crtc_to_ltdc(crtc);
struct drm_device *ddev = crtc->dev;
+ struct drm_connector_list_iter iter;
+ struct drm_connector *connector = NULL;
+ struct drm_encoder *encoder = NULL;
+ struct drm_bridge *bridge = NULL;
struct drm_display_mode *mode = &crtc->state->adjusted_mode;
struct videomode vm;
u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
u32 total_width, total_height;
+ u32 bus_flags = 0;
u32 val;
int ret;
+ /* get encoder from crtc */
+ drm_for_each_encoder(encoder, ddev)
+ if (encoder->crtc == crtc)
+ break;
+
+ if (encoder) {
+ /* get bridge from encoder */
+ list_for_each_entry(bridge, &encoder->bridge_chain, chain_node)
+ if (bridge->encoder == encoder)
+ break;
+
+ /* Get the connector from encoder */
+ drm_connector_list_iter_begin(ddev, &iter);
+ drm_for_each_connector_iter(connector, &iter)
+ if (connector->encoder == encoder)
+ break;
+ drm_connector_list_iter_end(&iter);
+ }
+
+ if (bridge && bridge->timings)
+ bus_flags = bridge->timings->input_bus_flags;
+ else if (connector)
+ bus_flags = connector->display_info.bus_flags;
+
if (!pm_runtime_active(ddev->dev)) {
ret = pm_runtime_get_sync(ddev->dev);
if (ret) {
@@ -586,10 +615,10 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
val |= GCR_VSPOL;
- if (vm.flags & DISPLAY_FLAGS_DE_LOW)
+ if (bus_flags & DRM_BUS_FLAG_DE_LOW)
val |= GCR_DEPOL;
- if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
+ if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
val |= GCR_PCPOL;
reg_update_bits(ldev->regs, LTDC_GCR,
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH V4] drm/stm: Fix bus_flags handling
2021-01-27 11:07 [PATCH V4] drm/stm: Fix bus_flags handling Marek Vasut
@ 2021-01-28 13:55 ` yannick Fertre
2021-02-15 17:43 ` Philippe CORNU
1 sibling, 0 replies; 3+ messages in thread
From: yannick Fertre @ 2021-01-28 13:55 UTC (permalink / raw)
To: Marek Vasut, dri-devel
Cc: Benjamin Gaignard, Antonio Borneo, Sam Ravnborg, Philippe Cornu,
Yannick Fertre, Maxime Coquelin, Vincent Abriou, linux-stm32,
linux-arm-kernel, Alexandre Torgue
Hi Marek,
Thanks for the patch.
Tested-by: Yannick Fertre <yannick.fertre@foss.st.com>
On 1/27/21 12:07 PM, Marek Vasut wrote:
> The drm_display_mode_to_videomode() does not populate DISPLAY_FLAGS_DE_LOW
> or DISPLAY_FLAGS_PIXDATA_NEGEDGE flags in struct videomode. Therefore, no
> matter what polarity the next bridge or display might require, these flags
> are never set, and thus the LTDC GCR_DEPOL and GCR_PCPOL bits are never set,
> and the LTDC behaves as if both DISPLAY_FLAGS_PIXDATA_POSEDGE and
> DISPLAY_FLAGS_DE_HIGH were always set.
>
> The fix for this problem is taken almost verbatim from MXSFB driver. In
> case there is a bridge attached to the LTDC, the bridge might have extra
> polarity requirements, so extract bus_flags from the bridge and use them
> for LTDC configuration. Otherwise, extract bus_flags from the connector,
> which is the display.
>
> Fixes: b759012c5fa7 ("drm/stm: Add STM32 LTDC driver")
> Signed-off-by: Marek Vasut <marex@denx.de>
> Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
> Cc: Alexandre Torgue <alexandre.torgue@st.com>
> Cc: Antonio Borneo <antonio.borneo@st.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: Philippe Cornu <philippe.cornu@st.com>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Cc: Vincent Abriou <vincent.abriou@st.com>
> Cc: Yannick Fertre <yannick.fertre@st.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-stm32@st-md-mailman.stormreply.com
> To: dri-devel@lists.freedesktop.org
> ---
> V2: Check if ldev->bridge->timings is non-NULL before accessing it
> V3: get bus_flags from connector (from Yannick)
> - Display controller could support several connectors (not connected at
> the same time). ie: stm32mp15c-DK2 board have 2 connectors (HDMI + DSI).
> Driver check which connector is connected to get the bus flag.
> V4: get bridge from encoder (from Yannick)
> ---
> drivers/gpu/drm/stm/ltdc.c | 33 +++++++++++++++++++++++++++++++--
> 1 file changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index 6e28e6b60e72..acc9f6694eb6 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -544,13 +544,42 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
> {
> struct ltdc_device *ldev = crtc_to_ltdc(crtc);
> struct drm_device *ddev = crtc->dev;
> + struct drm_connector_list_iter iter;
> + struct drm_connector *connector = NULL;
> + struct drm_encoder *encoder = NULL;
> + struct drm_bridge *bridge = NULL;
> struct drm_display_mode *mode = &crtc->state->adjusted_mode;
> struct videomode vm;
> u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
> u32 total_width, total_height;
> + u32 bus_flags = 0;
> u32 val;
> int ret;
>
> + /* get encoder from crtc */
> + drm_for_each_encoder(encoder, ddev)
> + if (encoder->crtc == crtc)
> + break;
> +
> + if (encoder) {
> + /* get bridge from encoder */
> + list_for_each_entry(bridge, &encoder->bridge_chain, chain_node)
> + if (bridge->encoder == encoder)
> + break;
> +
> + /* Get the connector from encoder */
> + drm_connector_list_iter_begin(ddev, &iter);
> + drm_for_each_connector_iter(connector, &iter)
> + if (connector->encoder == encoder)
> + break;
> + drm_connector_list_iter_end(&iter);
> + }
> +
> + if (bridge && bridge->timings)
> + bus_flags = bridge->timings->input_bus_flags;
> + else if (connector)
> + bus_flags = connector->display_info.bus_flags;
> +
> if (!pm_runtime_active(ddev->dev)) {
> ret = pm_runtime_get_sync(ddev->dev);
> if (ret) {
> @@ -586,10 +615,10 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
> if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
> val |= GCR_VSPOL;
>
> - if (vm.flags & DISPLAY_FLAGS_DE_LOW)
> + if (bus_flags & DRM_BUS_FLAG_DE_LOW)
> val |= GCR_DEPOL;
>
> - if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
> + if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
> val |= GCR_PCPOL;
>
> reg_update_bits(ldev->regs, LTDC_GCR,
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: [PATCH V4] drm/stm: Fix bus_flags handling
2021-01-27 11:07 [PATCH V4] drm/stm: Fix bus_flags handling Marek Vasut
2021-01-28 13:55 ` yannick Fertre
@ 2021-02-15 17:43 ` Philippe CORNU
1 sibling, 0 replies; 3+ messages in thread
From: Philippe CORNU @ 2021-02-15 17:43 UTC (permalink / raw)
To: Marek Vasut, dri-devel
Cc: Alexandre TORGUE, Antonio BORNEO, Vincent ABRIOU, Yannick FERTRE,
Maxime Coquelin, Sam Ravnborg, linux-stm32, linux-arm-kernel,
Benjamin Gaignard
Dear Marek,
Applied on drm-misc-next.
Many thanks for your patch,
Philippe :-)
ST Restricted
-----Original Message-----
From: Marek Vasut <marex@denx.de>
Sent: Wednesday, January 27, 2021 12:08
To: dri-devel@lists.freedesktop.org
Cc: Marek Vasut <marex@denx.de>; Yannick FERTRE <yannick.fertre@st.com>; Alexandre TORGUE <alexandre.torgue@st.com>; Antonio BORNEO <antonio.borneo@st.com>; Benjamin Gaignard <benjamin.gaignard@st.com>; Maxime Coquelin <mcoquelin.stm32@gmail.com>; Philippe CORNU <philippe.cornu@st.com>; Sam Ravnborg <sam@ravnborg.org>; Vincent ABRIOU <vincent.abriou@st.com>; linux-arm-kernel@lists.infradead.org; linux-stm32@st-md-mailman.stormreply.com
Subject: [PATCH V4] drm/stm: Fix bus_flags handling
The drm_display_mode_to_videomode() does not populate DISPLAY_FLAGS_DE_LOW or DISPLAY_FLAGS_PIXDATA_NEGEDGE flags in struct videomode. Therefore, no matter what polarity the next bridge or display might require, these flags are never set, and thus the LTDC GCR_DEPOL and GCR_PCPOL bits are never set, and the LTDC behaves as if both DISPLAY_FLAGS_PIXDATA_POSEDGE and DISPLAY_FLAGS_DE_HIGH were always set.
The fix for this problem is taken almost verbatim from MXSFB driver. In case there is a bridge attached to the LTDC, the bridge might have extra polarity requirements, so extract bus_flags from the bridge and use them for LTDC configuration. Otherwise, extract bus_flags from the connector, which is the display.
Fixes: b759012c5fa7 ("drm/stm: Add STM32 LTDC driver")
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Antonio Borneo <antonio.borneo@st.com>
Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Philippe Cornu <philippe.cornu@st.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Yannick Fertre <yannick.fertre@st.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: dri-devel@lists.freedesktop.org
---
V2: Check if ldev->bridge->timings is non-NULL before accessing it
V3: get bus_flags from connector (from Yannick)
- Display controller could support several connectors (not connected at
the same time). ie: stm32mp15c-DK2 board have 2 connectors (HDMI + DSI).
Driver check which connector is connected to get the bus flag.
V4: get bridge from encoder (from Yannick)
---
drivers/gpu/drm/stm/ltdc.c | 33 +++++++++++++++++++++++++++++++--
1 file changed, 31 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 6e28e6b60e72..acc9f6694eb6 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -544,13 +544,42 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc) {
struct ltdc_device *ldev = crtc_to_ltdc(crtc);
struct drm_device *ddev = crtc->dev;
+ struct drm_connector_list_iter iter;
+ struct drm_connector *connector = NULL;
+ struct drm_encoder *encoder = NULL;
+ struct drm_bridge *bridge = NULL;
struct drm_display_mode *mode = &crtc->state->adjusted_mode;
struct videomode vm;
u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
u32 total_width, total_height;
+ u32 bus_flags = 0;
u32 val;
int ret;
+ /* get encoder from crtc */
+ drm_for_each_encoder(encoder, ddev)
+ if (encoder->crtc == crtc)
+ break;
+
+ if (encoder) {
+ /* get bridge from encoder */
+ list_for_each_entry(bridge, &encoder->bridge_chain, chain_node)
+ if (bridge->encoder == encoder)
+ break;
+
+ /* Get the connector from encoder */
+ drm_connector_list_iter_begin(ddev, &iter);
+ drm_for_each_connector_iter(connector, &iter)
+ if (connector->encoder == encoder)
+ break;
+ drm_connector_list_iter_end(&iter);
+ }
+
+ if (bridge && bridge->timings)
+ bus_flags = bridge->timings->input_bus_flags;
+ else if (connector)
+ bus_flags = connector->display_info.bus_flags;
+
if (!pm_runtime_active(ddev->dev)) {
ret = pm_runtime_get_sync(ddev->dev);
if (ret) {
@@ -586,10 +615,10 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
val |= GCR_VSPOL;
- if (vm.flags & DISPLAY_FLAGS_DE_LOW)
+ if (bus_flags & DRM_BUS_FLAG_DE_LOW)
val |= GCR_DEPOL;
- if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
+ if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
val |= GCR_PCPOL;
reg_update_bits(ldev->regs, LTDC_GCR,
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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2021-01-27 11:07 [PATCH V4] drm/stm: Fix bus_flags handling Marek Vasut
2021-01-28 13:55 ` yannick Fertre
2021-02-15 17:43 ` Philippe CORNU
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