Hi
Am 19.02.25 um 08:57 schrieb Thomas Zimmermann:
Hi
Am 18.02.25 um 21:12 schrieb Aditya Garg:
Hi
In continuation to my previous mail.
+
+static int appletbdrm_send_msg(struct appletbdrm_device *adev, u32
msg)
+{
+ struct appletbdrm_msg_simple_request *request;
+ int ret;
+
+ request = kzalloc(sizeof(*request), GFP_KERNEL);
+ if (!request)
+ return -ENOMEM;
+
+ request->header.unk_00 = cpu_to_le16(2);
+ request->header.unk_02 = cpu_to_le16(0x1512);
+ request->header.size = cpu_to_le32(sizeof(*request) -
sizeof(request->header));
+ request->msg = msg;
+ request->size = request->header.size;
+
+ ret = appletbdrm_send_request(adev, &request->header,
sizeof(*request));
+
+ kfree(request);
This is temporary data for the send operation and save to free here?
Probably yes. If I understand correctly, it’s needed to make the
touchbar go into the display mode, from the hid keyboard mode.
We here are doing the same as the Windows driver [1] for this does.
[1]
https://github.com/imbushuo/DFRDisplayKm/blob/master/src/DFRDisplayKm/include/Dfr.h#L3
Yeah. My concern was that request is being freed while the USB send
operation is still using it. But in the USB code, it doesn't look like
that.
[...]
Can we void the use of drm_fb_blit()? Since you know all formats in
advance, just do
switch (format)
case XRGB8888: drm_fb_xrgb888_to_bgr888() break default:
drm_fb_memcpy() break }We use blit in simpledrm and ofdrm, where
we don't know the formats and output buffers in advance. But it's
really not so great in other drivers, I think.
I think you mean this:
#include <drm/drm_framebuffer.h>
switch (fb->format->format) {
case DRM_FORMAT_XRGB8888:
drm_fb_xrgb8888_to_bgr888(&dst, NULL,
&shadow_plane_state->data[0], fb, &damage,
&shadow_plane_state->fmtcnv_state);
break;
default:
drm_fb_memcpy(&dst, NULL, &shadow_plane_state->data[0],
fb, &damage);
break;
}
Yes.
[...]
For USB devices, we need special wiring to make PRIME work. The
PRIME device must support DMA, but a USB device doesn't. So we pass
the USB controller device instead. See [2] for what udl does and how
it obtains dmadev.
[2]
https://elixir.bootlin.com/linux/v6.14-rc3/source/drivers/gpu/drm/udl/udl_drv.c#L76
Disregard my previous reply for this. I believe you meant by this?:
—>8—
From b6fda730995b7f28374c1ff38778a6f3e6da65da Mon Sep 17 00:00:00 2001
From: Aditya Garg <gargaditya08@xxxxxxxx>
Date: Tue, 18 Feb 2025 22:47:44 +0530
Subject: [PATCH] prime
---
drivers/gpu/drm/tiny/appletbdrm.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/gpu/drm/tiny/appletbdrm.c
b/drivers/gpu/drm/tiny/appletbdrm.c
index f2d911325..b835063c2 100644
--- a/drivers/gpu/drm/tiny/appletbdrm.c
+++ b/drivers/gpu/drm/tiny/appletbdrm.c
@@ -118,6 +118,7 @@ struct appletbdrm_fb_request_response {
struct appletbdrm_device {
struct device *dev;
+ struct device *dmadev;
unsigned int in_ep;
unsigned int out_ep;
@@ -521,10 +522,22 @@ static const struct drm_encoder_funcs
appletbdrm_encoder_funcs = {
.destroy = drm_encoder_cleanup,
};
+static struct drm_gem_object
*appletbdrm_driver_gem_prime_import(struct drm_device *dev,
+ struct dma_buf *dma_buf)
+{
+ struct appletbdrm_device *adev = drm_to_adev(dev);
+
+ if (!adev->dmadev)
+ return ERR_PTR(-ENODEV);
+
+ return drm_gem_prime_import_dev(dev, dma_buf, adev->dmadev);
+}
+
DEFINE_DRM_GEM_FOPS(appletbdrm_drm_fops);
static const struct drm_driver appletbdrm_drm_driver = {
DRM_GEM_SHMEM_DRIVER_OPS,
+ .gem_prime_import = appletbdrm_driver_gem_prime_import,
Exactly. The TODO item for this problem is at [1], but there's quite a
bit of change involved to fix it. Setting a dedicated DMA device is
the next best thing.
[1]
https://elixir.bootlin.com/linux/v6.13.3/source/Documentation/gpu/todo.rst#L615
To add to this: you also have to set dmadev. See [2] for the respective
code in udl. And please git-grep udl for dmadev and look for the places
were it handles device ref-counting.
[2]
https://elixir.bootlin.com/linux/v6.13.2/source/drivers/gpu/drm/udl/udl_main.c#L314
Best regards
Thomas
Best regards
Thomas
.name = "appletbdrm",
.desc = "Apple Touch Bar DRM Driver",
.major = 1,
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
