Re: [PATCH v2] drm/msm/dsi: Enable DATABUS_WIDEN for DSI command mode
From: Jessica Zhang
Date: Mon Jul 17 2023 - 20:31:32 EST
On 7/14/2023 6:38 PM, Dmitry Baryshkov wrote:
On 15/07/2023 03:59, Jessica Zhang wrote:
On 7/14/2023 3:30 PM, Dmitry Baryshkov wrote:
On Fri, 14 Jul 2023 at 22:03, Jessica Zhang
<quic_jesszhan@xxxxxxxxxxx> wrote:
On 7/13/2023 6:23 PM, Dmitry Baryshkov wrote:
On 14/07/2023 03:21, Jessica Zhang wrote:
DSI 6G v2.5.x+ and DPU 7.x+ support a data-bus widen mode that
allows DSI
to send 48 bits of compressed data per pclk instead of 24.
For all chipsets that support this mode, enable it whenever DSC is
enabled as recommended by the hardware programming guide.
Only enable this for command mode as we are currently unable to
validate
it for video mode.
Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
---
Note: The dsi.xml.h changes were generated using the headergen2
script in
envytools [2], but the changes to the copyright and rules-ng-ng
source
file
paths were dropped.
Separate commit please, so that it can be replaced by headers sync
with
Mesa3d.
Hi Dmitry,
Acked.
[1] https://patchwork.freedesktop.org/series/120580/
[2] https://github.com/freedreno/envytools/
--
Changes in v2:
- Rebased on top of "drm/msm/dpu: Re-introduce dpu core revision"
- Squashed all commits to avoid breaking feature if the series is
only
partially applied
No. Please unsquash it. Please design the series so that the patches
work even if it is only partially applied.
Acked.
- Moved DATABUS_WIDEN bit setting to dsi_ctr_enable() (Marijn)
- Have DPU check if wide bus is requested by output driver (Dmitry)
- Introduced bytes_per_pclk variable for dsi_timing_setup() hdisplay
adjustment (Marijn)
- Link to v1:
https://lore.kernel.org/r/20230525-add-widebus-support-v1-0-c7069f2efca1@xxxxxxxxxxx
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 10 ++++++----
.../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 4 +++-
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c | 3 +++
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h | 1 +
drivers/gpu/drm/msm/dsi/dsi.c | 5 +++++
drivers/gpu/drm/msm/dsi/dsi.h | 1 +
drivers/gpu/drm/msm/dsi/dsi.xml.h | 1 +
drivers/gpu/drm/msm/dsi/dsi_host.c | 23
+++++++++++++++++++++-
drivers/gpu/drm/msm/msm_drv.h | 6 ++++++
9 files changed, 48 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index f0a2a1dca741..6aed63c06c1d 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -2411,6 +2411,7 @@ struct drm_encoder *dpu_encoder_init(struct
drm_device *dev,
struct dpu_kms *dpu_kms = to_dpu_kms(priv->kms);
struct drm_encoder *drm_enc = NULL;
struct dpu_encoder_virt *dpu_enc = NULL;
+ int index = disp_info->h_tile_instance[0];
int ret = 0;
dpu_enc = devm_kzalloc(dev->dev, sizeof(*dpu_enc),
GFP_KERNEL);
@@ -2439,13 +2440,14 @@ struct drm_encoder *dpu_encoder_init(struct
drm_device *dev,
timer_setup(&dpu_enc->frame_done_timer,
dpu_encoder_frame_done_timeout, 0);
- if (disp_info->intf_type == INTF_DSI)
+ if (disp_info->intf_type == INTF_DSI) {
timer_setup(&dpu_enc->vsync_event_timer,
dpu_encoder_vsync_event_handler,
While you are touching this part, could you please drop
dpu_encoder_vsync_event_handler() and
dpu_encoder_vsync_event_work_handler(), they are useless?
Since these calls aren't related to widebus, I don't think I'll include
it in this series. However, I can post this cleanup as a separate patch
and add that as a dependency if that's ok.
Sure, that will work for me. Thank you!
0);
- else if (disp_info->intf_type == INTF_DP)
- dpu_enc->wide_bus_en = msm_dp_wide_bus_available(
- priv->dp[disp_info->h_tile_instance[0]]);
+ dpu_enc->wide_bus_en =
msm_dsi_is_widebus_enabled(priv->dsi[index]);
+ } else if (disp_info->intf_type == INTF_DP) {
+ dpu_enc->wide_bus_en =
msm_dp_wide_bus_available(priv->dp[index]);
+ }
INIT_DELAYED_WORK(&dpu_enc->delayed_off_work,
dpu_encoder_off_work);
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
index df88358e7037..dace6168be2d 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
@@ -69,8 +69,10 @@ static void _dpu_encoder_phys_cmd_update_intf_cfg(
phys_enc->hw_intf,
phys_enc->hw_pp->idx);
- if (intf_cfg.dsc != 0)
+ if (intf_cfg.dsc != 0) {
cmd_mode_cfg.data_compress = true;
+ cmd_mode_cfg.wide_bus_en =
dpu_encoder_is_widebus_enabled(phys_enc->parent);
+ }
if (phys_enc->hw_intf->ops.program_intf_cmd_cfg)
phys_enc->hw_intf->ops.program_intf_cmd_cfg(phys_enc->hw_intf,
&cmd_mode_cfg);
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
index 8ec6505d9e78..dc6f3febb574 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
@@ -521,6 +521,9 @@ static void
dpu_hw_intf_program_intf_cmd_cfg(struct dpu_hw_intf *ctx,
if (cmd_mode_cfg->data_compress)
intf_cfg2 |= INTF_CFG2_DCE_DATA_COMPRESS;
+ if (cmd_mode_cfg->wide_bus_en)
+ intf_cfg2 |= INTF_CFG2_DATABUS_WIDEN;
+
DPU_REG_WRITE(&ctx->hw, INTF_CONFIG2, intf_cfg2);
}
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
index 77f80531782b..c539025c418b 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
@@ -50,6 +50,7 @@ struct dpu_hw_intf_status {
struct dpu_hw_intf_cmd_mode_cfg {
u8 data_compress; /* enable data compress between dpu
and dsi */
+ u8 wide_bus_en; /* enable databus widen mode */
};
/**
diff --git a/drivers/gpu/drm/msm/dsi/dsi.c
b/drivers/gpu/drm/msm/dsi/dsi.c
index baab79ab6e74..e3cc06c94397 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.c
+++ b/drivers/gpu/drm/msm/dsi/dsi.c
@@ -17,6 +17,11 @@ struct drm_dsc_config
*msm_dsi_get_dsc_config(struct msm_dsi *msm_dsi)
return msm_dsi_host_get_dsc_config(msm_dsi->host);
}
+bool msm_dsi_is_widebus_enabled(struct msm_dsi *msm_dsi)
+{
+ return msm_dsi_host_is_widebus_supported(msm_dsi->host);
This is incorrect. It will enable widebus even for non-DSC cases.
FWIW, all calls for msm_dsi_is_widebus_enabled() and
msm_dsi_host_is_widebus_supported() are guarded by a DSC check.
That being said, I also see your point that
msm_dsi_is_widebus_enabled()
is an incorrect name since this will only check if widebus is
supported.
Maybe a better change would be to change msm_dsi_is_widebus_enabled to
*_is_widebus_supported(), move the setting of dpu_enc->wide_bus_en for
both DP and DSI to dpu_encoder_virt_atomic_enable(), then for DSI set
wide_bus_en = dpu_enc->dsc && dsi_is_widebus_supported().
I think we should change msm_dp_wide_bus_available() to
msm_dp_wide_bus_enabled(). We don't have a way to tell DP (or DSI) if
widebus really should be enabled or not. So it would be better to make
DP and DSI drivers provide is_widebus_enabled function.
I think making changes to the DP API is outside the scope of this
series since these changes are focused on supporting widebus for DSI
specifically.
Sure, the DP can be handled separately, if we agree on the API.
+}
+
static int dsi_get_phy(struct msm_dsi *msm_dsi)
{
struct platform_device *pdev = msm_dsi->pdev;
diff --git a/drivers/gpu/drm/msm/dsi/dsi.h
b/drivers/gpu/drm/msm/dsi/dsi.h
index bd3763a5d723..219a9f756759 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.h
+++ b/drivers/gpu/drm/msm/dsi/dsi.h
@@ -134,6 +134,7 @@ int dsi_calc_clk_rate_6g(struct msm_dsi_host
*msm_host, bool is_bonded_dsi);
void msm_dsi_host_snapshot(struct msm_disp_state *disp_state,
struct
mipi_dsi_host *host);
void msm_dsi_host_test_pattern_en(struct mipi_dsi_host *host);
struct drm_dsc_config *msm_dsi_host_get_dsc_config(struct
mipi_dsi_host *host);
+bool msm_dsi_host_is_widebus_supported(struct mipi_dsi_host *host);
/* dsi phy */
struct msm_dsi_phy;
diff --git a/drivers/gpu/drm/msm/dsi/dsi.xml.h
b/drivers/gpu/drm/msm/dsi/dsi.xml.h
index a4a154601114..2a7d980e12c3 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.xml.h
+++ b/drivers/gpu/drm/msm/dsi/dsi.xml.h
@@ -664,6 +664,7 @@ static inline uint32_t
DSI_CMD_MODE_MDP_CTRL2_INPUT_RGB_SWAP(enum dsi_rgb_swap v
return ((val) <<
DSI_CMD_MODE_MDP_CTRL2_INPUT_RGB_SWAP__SHIFT) &
DSI_CMD_MODE_MDP_CTRL2_INPUT_RGB_SWAP__MASK;
}
#define DSI_CMD_MODE_MDP_CTRL2_BURST_MODE 0x00010000
+#define DSI_CMD_MODE_MDP_CTRL2_DATABUS_WIDEN 0x00100000
#define REG_DSI_CMD_MODE_MDP_STREAM2_CTRL 0x000001b8
#define DSI_CMD_MODE_MDP_STREAM2_CTRL_DATA_TYPE__MASK 0x0000003f
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c
b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 645927214871..6ea3476acf0d 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -710,6 +710,14 @@ static void dsi_ctrl_disable(struct msm_dsi_host
*msm_host)
dsi_write(msm_host, REG_DSI_CTRL, 0);
}
+bool msm_dsi_host_is_widebus_supported(struct mipi_dsi_host *host)
+{
+ struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+
+ return msm_host->cfg_hnd->major == MSM_DSI_VER_MAJOR_6G &&
+ msm_host->cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V2_5_0;
Would it be better to push it to the config data, like we did for DP?
I don't think so -- I think adding it to the config data as a feature
flag would bloat dsi_cfg.c. It would be simpler and cleaner (IMO) to
keep this as a version check.
Ok.
+}
+
static void dsi_ctrl_enable(struct msm_dsi_host *msm_host,
struct msm_dsi_phy_shared_timings *phy_shared_timings,
struct msm_dsi_phy *phy)
{
@@ -757,6 +765,11 @@ static void dsi_ctrl_enable(struct msm_dsi_host
*msm_host,
msm_host->cfg_hnd->minor >=
MSM_DSI_6G_VER_MINOR_V1_3) {
data = dsi_read(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2);
data |= DSI_CMD_MODE_MDP_CTRL2_BURST_MODE;
+
+ /* TODO: Allow for video-mode support once
tested/fixed */
+ if (msm_host->cfg_hnd->minor >=
MSM_DSI_6G_VER_MINOR_V2_5_0 && msm_host->dsc)
msm_dsi_is_widebus_enabled() && msm_host->dsc
*_is_widebus_enabled() also checks for major version >= 6G, so calling
it here would be a bit redundant as we're already checking for that
earlier.
However now you have different checks in two different places.
My suggestion is to have the function msm_dsi_is_widebus_supported(),
which the rest of the code uses to check if wide bus is actually
enabled in the HW. If at some point DSI 2.11 drops wide bus support,
I'd like to see a change at a single place, rather than having changes
all over the code.
Ok, I think this is a fair point. The main reason I just had the minor
version check here was to avoid the redundant major version check from
the BURST_MODE conditional [1].
What if we just move the MDP_CTRL2 configuration to a separate
function and do the BURST_MODE and DATABUS_WIDEN checks separately?
I think that a function that just writes MDP_CTRL2 is an overkill.
Moving video / CMD setup to separate functions to be called from
dsi_ctrl_enable sounds like a better idea.
Got it -- will have a separate mdp_ctrl2_config_cmd_mode() helper.
So, something like:
```
bool burst_supported()
{
return major >= 6g && minor >= 1.3;
}
bool widebus_supported()
{
return major >= 6g && minor >= 2.5;
}
void program_cmd_mdp_ctrl2()
{
if (major < 6g)
return;
data = read(mdp_ctrl2);
if (burst_supported)
data |= burst;
if (widebus_supported)
Two issues with this piece of code.
First, you are splitting the 6g and minor checks. Please don't do this.
If might be obvious now, but it is better to keep full condition in one
place, even if it looks redundant to you. The compiler will do its jobs
and make sure that all expressions are evaluated only once. And this is
especially true for widebus, since the driver checks this condition
several times.
The reason the major and minor checks are split here is because
MDP_CTRL2 is only present in DSI 6G.
Second problem (which is quite specific to widebus): in this fragment of
code you say that if widebus is supported, it should be enabled. But it
is not true: we should not be enabling widebus if this is not a DSC
mode. So, I will be insisting on is_enabled() kind of function.
I can add a DSC check here, but have some concerns about the
*_is_enabled() function. Please refer to my response below.
data |= widebus;
write(mdp_ctrl2, data);
}
void dsi_ctrl_enable()
{
...
program_cmd_mdp_ctrl2();
...
}
```
Likewise I'd like to have the function msm_dsi_is_widebus_enabled(),
which is used by the rest of the code to check if the widebus should
be actually enabled.
Actually I think we can even drop the is_supported at all() and use
the following code:
bool msm_dsi_is_widebus_enabled()
{
if (major < 6G || minor < V2_5_0)
return false;
return !!msm_host->dsc;
I'd rather keep this API as *_is_widebus_supported() or
*_is_widebus_available() (if you'd like it to match DP) and have the
DSC check outside.
This is because we already guard for DSC in DSI for the
dsi_timing_setup() hdisplay adjustments and for the DPU hw_intf
widebus register configuration. The only place where a DSC check
needed to be added was for the MDP_CTRL2 configuration.
So, since most places can already use preexisting DSC checks, having
another DSC check within msm_dsi_is_widebus_enabled() would either be
redundant or require extensive refactoring to justify adding the check
here.
As I wrote, I'd prefer using a single is_enabled() function all over the
code to optimizing / removing redundancy in C expressions. If for some
reason the HPG suggests enabling widebus for non-DSC modes (or e.g.
disabling it for yuv4:2:0 DSC), I do not want to have this check
scattered between different places (with a high likelyhood of missing
the most obvious place).
This is the place where DSI differs from DP. For DP and widebus it was
really simple: available => enabled.
Sorry if I didn't make this clear enough earlier, but I think the issue
with having a single *_is_widebus_enabled() function is that it will
cause redundant checks -- specifically in dsi_timing_setup() where the
DSC hdisplay adjustment (that depends on widebus) is already wrapped in
an `if (msm_host->dsc)` check. We'd either have to find a workaround to
avoid having a redundant `if (dsc)` check, or do a minor version check
for this instance.
In addition, *_is_widebus_enabled() would only work under the assumption
that DSC (if supported) will always be enabled during bootup for DSI. If
there ends up being support for a panel that allows for DSC to be
enabled on the fly after bootup, the proposed *_is_widebus_enabled()
check would break since the assumption that DSC is always enabled on
bootup would not be true anymore.
Thanks,
Jessica Zhang
Thanks,
Jessica Zhang
}
Then the rest of the code should call this function only.
FWIW, I've nested the widebus configuration within the burst mode
configuration to keep it so that we only have to read/write the
MDP_CTRL2 once.
+ data |= DSI_CMD_MODE_MDP_CTRL2_DATABUS_WIDEN;
+
dsi_write(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2, data);
}
}
@@ -894,6 +907,7 @@ static void dsi_timing_setup(struct msm_dsi_host
*msm_host, bool is_bonded_dsi)
u32 hdisplay = mode->hdisplay;
u32 wc;
int ret;
+ bool widebus_supported =
msm_dsi_host_is_widebus_supported(&msm_host->base);
s/supported/enabled for this function.
I would like to keep the name as *_is_widebus_supported() since it
better reflects the functionality of the helper.
FWIW, the widebus hdisplay adjustments are already guarded by a DSC
check.
See my previous comment.
Thanks,
Jessica Zhang
DBG("");
@@ -914,6 +928,7 @@ static void dsi_timing_setup(struct msm_dsi_host
*msm_host, bool is_bonded_dsi)
if (msm_host->dsc) {
struct drm_dsc_config *dsc = msm_host->dsc;
+ u32 bytes_per_pclk;
/* update dsc params with timing params */
if (!dsc || !mode->hdisplay || !mode->vdisplay) {
@@ -937,7 +952,13 @@ static void dsi_timing_setup(struct msm_dsi_host
*msm_host, bool is_bonded_dsi)
* pulse width same
*/
h_total -= hdisplay;
- hdisplay =
DIV_ROUND_UP(msm_dsc_get_bytes_per_line(msm_host->dsc), 3);
+ if (widebus_supported && !(msm_host->mode_flags &
MIPI_DSI_MODE_VIDEO))
+ bytes_per_pclk = 6;
+ else
+ bytes_per_pclk = 3;
+
+ hdisplay =
DIV_ROUND_UP(msm_dsc_get_bytes_per_line(msm_host->dsc),
bytes_per_pclk);
+
h_total += hdisplay;
ha_end = ha_start + hdisplay;
}
diff --git a/drivers/gpu/drm/msm/msm_drv.h
b/drivers/gpu/drm/msm/msm_drv.h
index 9d9d5e009163..7ff56d09014c 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -344,6 +344,7 @@ void msm_dsi_snapshot(struct msm_disp_state
*disp_state, struct msm_dsi *msm_dsi
bool msm_dsi_is_cmd_mode(struct msm_dsi *msm_dsi);
bool msm_dsi_is_bonded_dsi(struct msm_dsi *msm_dsi);
bool msm_dsi_is_master_dsi(struct msm_dsi *msm_dsi);
+bool msm_dsi_is_widebus_enabled(struct msm_dsi *msm_dsi);
struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi
*msm_dsi);
#else
static inline void __init msm_dsi_register(void)
@@ -374,6 +375,11 @@ static inline bool msm_dsi_is_master_dsi(struct
msm_dsi *msm_dsi)
return false;
}
+static inline bool msm_dsi_is_widebus_enabled(struct msm_dsi
*msm_dsi)
+{
+ return false;
+}
+
static inline struct drm_dsc_config *msm_dsi_get_dsc_config(struct
msm_dsi *msm_dsi)
{
return NULL;
---
base-commit: 9445fc2942a890e84c74e170ebd7dfb9566e3357
change-id: 20230525-add-widebus-support-f785546ee751
Best regards,
--
With best wishes
Dmitry
--
With best wishes
Dmitry
--
With best wishes
Dmitry