RE: [PATCH v2 4/8] drm: xlnx: zynqmp_dpsub: Minimize usage of global flag
Hi Laurent,
Thank you for the review.
> -Original Message-
> From: Laurent Pinchart
> Sent: Monday, March 18, 2024 5:13 PM
> To: Klymenko, Anatoliy
> Cc: Maarten Lankhorst ; Maxime Ripard
> ; Thomas Zimmermann ; David
> Airlie ; Daniel Vetter ; Simek, Michal
> ; Andrzej Hajda ; Neil
> Armstrong ; Robert Foss ; Jonas
> Karlman ; Jernej Skrabec ; Rob
> Herring ; Krzysztof Kozlowski
> ; Conor Dooley ;
> Mauro Carvalho Chehab ; dri-
> de...@lists.freedesktop.org; linux-arm-ker...@lists.infradead.org; linux-
> ker...@vger.kernel.org; devicet...@vger.kernel.org; linux-
> me...@vger.kernel.org
> Subject: Re: [PATCH v2 4/8] drm: xlnx: zynqmp_dpsub: Minimize usage of global
> flag
>
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>
>
> Hi Anatoliy,
>
> Thank you for the patch.
>
> On Tue, Mar 12, 2024 at 05:55:01PM -0700, Anatoliy Klymenko wrote:
> > Avoid usage of global zynqmp_dpsub.dma_enabled flag in DPSUB layer
> > context. This flag signals whether the driver runs in DRM CRTC or DRM
> > bridge mode, assuming that all display layers share the same live or
> > non-live mode of operation. Using per-layer mode instead of global
> > flag will siplify future support of the hybrid scenario.
>
> s/siplify/simplify/
>
> > Signed-off-by: Anatoliy Klymenko
> > ---
> > drivers/gpu/drm/xlnx/zynqmp_disp.c | 11 ---
> > 1 file changed, 4 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c
> > b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> > index af851190f447..dd48fa60fa9a 100644
> > --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
> > +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> > @@ -975,7 +975,7 @@ void zynqmp_disp_layer_disable(struct
> > zynqmp_disp_layer *layer) {
> > unsigned int i;
> >
> > - if (layer->disp->dpsub->dma_enabled) {
> > + if (layer->mode == ZYNQMP_DPSUB_LAYER_NONLIVE) {
> > for (i = 0; i < layer->drm_fmt->num_planes; i++)
> > dmaengine_terminate_sync(layer->dmas[i].chan);
> > }
> > @@ -1001,7 +1001,7 @@ void zynqmp_disp_layer_set_format(struct
> > zynqmp_disp_layer *layer,
> >
> > zynqmp_disp_avbuf_set_format(layer->disp, layer,
> > layer->disp_fmt);
> >
> > - if (!layer->disp->dpsub->dma_enabled)
> > + if (layer->mode == ZYNQMP_DPSUB_LAYER_LIVE)
> > return;
> >
> > /*
> > @@ -1039,7 +1039,7 @@ int zynqmp_disp_layer_update(struct
> zynqmp_disp_layer *layer,
> > const struct drm_format_info *info = layer->drm_fmt;
> > unsigned int i;
> >
> > - if (!layer->disp->dpsub->dma_enabled)
> > + if (layer->mode == ZYNQMP_DPSUB_LAYER_LIVE)
> > return 0;
>
> The above changes look nice.
>
> >
> > for (i = 0; i < info->num_planes; i++) { @@ -1089,7 +1089,7 @@
> > static void zynqmp_disp_layer_release_dma(struct zynqmp_disp *disp, {
> > unsigned int i;
> >
> > - if (!layer->info || !disp->dpsub->dma_enabled)
> > + if (!layer->info)
>
> This, however, doesn't seem right, as this function is called unconditionally
> from
> the remove path. The change below seems weird too.
> If I'm missing something, it should at least be explained in the commit
> message.
>
Actually, this whole condition should be removed, as now we're setting
layer.info for all types of layers. On top of that, we're setting the number of
DMA channels to zero for the live layers, which in turn prevents any DMA
channel initialization or release. You are right - that probably should be
mentioned explicitly in the commit message. I'll update it.
> > return;
> >
> > for (i = 0; i < layer->info->num_channels; i++) { @@ -1132,9
> > +1132,6 @@ static int zynqmp_disp_layer_request_dma(struct zynqmp_disp
> *disp,
> > unsigned int i;
> > int ret;
> >
> > - if (!disp->dpsub->dma_enabled)
> > - return 0;
> > -
> > for (i = 0; i < layer->info->num_channels; i++) {
> > struct zynqmp_disp_layer_dma *dma = >dmas[i];
> > char dma_channel_name[16];
> >
>
> --
> Regards,
>
> Laurent Pinchart
Thank you,
Anatoliy
Re: [PATCH v2 4/8] drm: xlnx: zynqmp_dpsub: Minimize usage of global flag
Hi Anatoliy,
Thank you for the patch.
On Tue, Mar 12, 2024 at 05:55:01PM -0700, Anatoliy Klymenko wrote:
> Avoid usage of global zynqmp_dpsub.dma_enabled flag in DPSUB layer
> context. This flag signals whether the driver runs in DRM CRTC or DRM
> bridge mode, assuming that all display layers share the same live or
> non-live mode of operation. Using per-layer mode instead of global flag
> will siplify future support of the hybrid scenario.
s/siplify/simplify/
> Signed-off-by: Anatoliy Klymenko
> ---
> drivers/gpu/drm/xlnx/zynqmp_disp.c | 11 ---
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c
> b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> index af851190f447..dd48fa60fa9a 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> @@ -975,7 +975,7 @@ void zynqmp_disp_layer_disable(struct zynqmp_disp_layer
> *layer)
> {
> unsigned int i;
>
> - if (layer->disp->dpsub->dma_enabled) {
> + if (layer->mode == ZYNQMP_DPSUB_LAYER_NONLIVE) {
> for (i = 0; i < layer->drm_fmt->num_planes; i++)
> dmaengine_terminate_sync(layer->dmas[i].chan);
> }
> @@ -1001,7 +1001,7 @@ void zynqmp_disp_layer_set_format(struct
> zynqmp_disp_layer *layer,
>
> zynqmp_disp_avbuf_set_format(layer->disp, layer, layer->disp_fmt);
>
> - if (!layer->disp->dpsub->dma_enabled)
> + if (layer->mode == ZYNQMP_DPSUB_LAYER_LIVE)
> return;
>
> /*
> @@ -1039,7 +1039,7 @@ int zynqmp_disp_layer_update(struct zynqmp_disp_layer
> *layer,
> const struct drm_format_info *info = layer->drm_fmt;
> unsigned int i;
>
> - if (!layer->disp->dpsub->dma_enabled)
> + if (layer->mode == ZYNQMP_DPSUB_LAYER_LIVE)
> return 0;
The above changes look nice.
>
> for (i = 0; i < info->num_planes; i++) {
> @@ -1089,7 +1089,7 @@ static void zynqmp_disp_layer_release_dma(struct
> zynqmp_disp *disp,
> {
> unsigned int i;
>
> - if (!layer->info || !disp->dpsub->dma_enabled)
> + if (!layer->info)
This, however, doesn't seem right, as this function is called
unconditionally from the remove path. The change below seems weird too.
If I'm missing something, it should at least be explained in the commit
message.
> return;
>
> for (i = 0; i < layer->info->num_channels; i++) {
> @@ -1132,9 +1132,6 @@ static int zynqmp_disp_layer_request_dma(struct
> zynqmp_disp *disp,
> unsigned int i;
> int ret;
>
> - if (!disp->dpsub->dma_enabled)
> - return 0;
> -
> for (i = 0; i < layer->info->num_channels; i++) {
> struct zynqmp_disp_layer_dma *dma = >dmas[i];
> char dma_channel_name[16];
>
--
Regards,
Laurent Pinchart
[PATCH v2 4/8] drm: xlnx: zynqmp_dpsub: Minimize usage of global flag
Avoid usage of global zynqmp_dpsub.dma_enabled flag in DPSUB layer
context. This flag signals whether the driver runs in DRM CRTC or DRM
bridge mode, assuming that all display layers share the same live or
non-live mode of operation. Using per-layer mode instead of global flag
will siplify future support of the hybrid scenario.
Signed-off-by: Anatoliy Klymenko
---
drivers/gpu/drm/xlnx/zynqmp_disp.c | 11 ---
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c
b/drivers/gpu/drm/xlnx/zynqmp_disp.c
index af851190f447..dd48fa60fa9a 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
@@ -975,7 +975,7 @@ void zynqmp_disp_layer_disable(struct zynqmp_disp_layer
*layer)
{
unsigned int i;
- if (layer->disp->dpsub->dma_enabled) {
+ if (layer->mode == ZYNQMP_DPSUB_LAYER_NONLIVE) {
for (i = 0; i < layer->drm_fmt->num_planes; i++)
dmaengine_terminate_sync(layer->dmas[i].chan);
}
@@ -1001,7 +1001,7 @@ void zynqmp_disp_layer_set_format(struct
zynqmp_disp_layer *layer,
zynqmp_disp_avbuf_set_format(layer->disp, layer, layer->disp_fmt);
- if (!layer->disp->dpsub->dma_enabled)
+ if (layer->mode == ZYNQMP_DPSUB_LAYER_LIVE)
return;
/*
@@ -1039,7 +1039,7 @@ int zynqmp_disp_layer_update(struct zynqmp_disp_layer
*layer,
const struct drm_format_info *info = layer->drm_fmt;
unsigned int i;
- if (!layer->disp->dpsub->dma_enabled)
+ if (layer->mode == ZYNQMP_DPSUB_LAYER_LIVE)
return 0;
for (i = 0; i < info->num_planes; i++) {
@@ -1089,7 +1089,7 @@ static void zynqmp_disp_layer_release_dma(struct
zynqmp_disp *disp,
{
unsigned int i;
- if (!layer->info || !disp->dpsub->dma_enabled)
+ if (!layer->info)
return;
for (i = 0; i < layer->info->num_channels; i++) {
@@ -1132,9 +1132,6 @@ static int zynqmp_disp_layer_request_dma(struct
zynqmp_disp *disp,
unsigned int i;
int ret;
- if (!disp->dpsub->dma_enabled)
- return 0;
-
for (i = 0; i < layer->info->num_channels; i++) {
struct zynqmp_disp_layer_dma *dma = >dmas[i];
char dma_channel_name[16];
--
2.25.1
