[PATCH 1/2] drm/gud: Add Raspberry Pi Pico ID

[PATCH 1/2] drm/gud: Add Raspberry Pi Pico ID

[Noralf Trønnes]

Add VID/PID for the Raspberry Pi Pico implementation.
Source: https://github.com/notro/gud-pico

Cc: Peter Stuge <peter@stuge.se>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---
 drivers/gpu/drm/gud/gud_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/gud/gud_drv.c b/drivers/gpu/drm/gud/gud_drv.c
index d02f8e968aad..eb4e08846da4 100644
--- a/drivers/gpu/drm/gud/gud_drv.c
+++ b/drivers/gpu/drm/gud/gud_drv.c
@@ -660,6 +660,7 @@ static int gud_resume(struct usb_interface *intf)
 
 static const struct usb_device_id gud_id_table[] = {
 	{ USB_DEVICE_INTERFACE_CLASS(0x1d50, 0x614d, USB_CLASS_VENDOR_SPEC) },
+	{ USB_DEVICE_INTERFACE_CLASS(0x16d0, 0x10a9, USB_CLASS_VENDOR_SPEC) },
 	{ }
 };
 
-- 
2.23.0

[PATCH 2/2] drm/gud: Add async_flush module parameter

[Noralf Trønnes]

Provide a way for userspace to choose synchronous flushing/pageflips.
This helps save CPU and power.

It is also useful for test scripts since userspace can know when a flush
has happended and wait before doing the next visual test.

Cc: Peter Stuge <peter@stuge.se>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---
 drivers/gpu/drm/gud/gud_pipe.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
index e0fb6cc969a3..8f56bf618ac2 100644
--- a/drivers/gpu/drm/gud/gud_pipe.c
+++ b/drivers/gpu/drm/gud/gud_pipe.c
@@ -23,6 +23,19 @@
 
 #include "gud_internal.h"
 
+/*
+ * Some userspace rendering loops runs all displays in the same loop.
+ * This means that a fast display will have to wait for a slow one.
+ * For this reason gud does flushing asynchronous by default.
+ * The down side is that in e.g. a single display setup userspace thinks
+ * the display is insanely fast since the driver reports back immediately
+ * that the flush/pageflip is done. This wastes CPU and power.
+ * Such users might want to set this module parameter to false.
+ */
+static bool gud_async_flush = true;
+module_param_named(async_flush, gud_async_flush, bool, 0644);
+MODULE_PARM_DESC(async_flush, "Enable asynchronous flushing [default=true]");
+
 /*
  * FIXME: The driver is probably broken on Big Endian machines.
  * See discussion:
@@ -578,6 +591,8 @@ void gud_pipe_update(struct drm_simple_display_pipe *pipe,
 		if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE)
 			drm_rect_init(&damage, 0, 0, fb->width, fb->height);
 		gud_fb_queue_damage(gdrm, fb, &damage);
+		if (!gud_async_flush)
+			flush_work(&gdrm->work);
 	}
 
 	if (!crtc->state->enable)
-- 
2.23.0

Re: [PATCH 1/2] drm/gud: Add Raspberry Pi Pico ID

[Peter Stuge]

Hi Noralf,

Noralf Trønnes wrote:
> Add VID/PID for the Raspberry Pi Pico implementation.
> Source: https://github.com/notro/gud-pico
> 
> +++ b/drivers/gpu/drm/gud/gud_drv.c
> @@ -660,6 +660,7 @@ static int gud_resume(struct usb_interface *intf)
>  
>  static const struct usb_device_id gud_id_table[] = {
>  	{ USB_DEVICE_INTERFACE_CLASS(0x1d50, 0x614d, USB_CLASS_VENDOR_SPEC) },
> +	{ USB_DEVICE_INTERFACE_CLASS(0x16d0, 0x10a9, USB_CLASS_VENDOR_SPEC) },
>  	{ }
>  };

A VID/PID isn't neccessarily tied to one implementation; as long as an
implementation is in fact compatible with the driver I consider it okay
to reuse a VID/PID, and the 0x1d50 conditions are met by gud-pico too.
That said, there's no harm in adding another id. :)

Reviewed-by: Peter Stuge <peter@stuge.se>


//Peter

Re: [PATCH 2/2] drm/gud: Add async_flush module parameter

[Peter Stuge]

Noralf Trønnes wrote:
> Provide a way for userspace to choose synchronous flushing/pageflips.
> This helps save CPU and power.
> 
> It is also useful for test scripts since userspace can know when a flush
> has happended and wait before doing the next visual test.
> 
> Cc: Peter Stuge <peter@stuge.se>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Reviewed-by: Peter Stuge <peter@stuge.se>

Re: [PATCH 1/2] drm/gud: Add Raspberry Pi Pico ID

[Noralf Trønnes]

Den 03.07.2021 21.24, skrev Peter Stuge:
> Hi Noralf,
> 
> Noralf Trønnes wrote:
>> Add VID/PID for the Raspberry Pi Pico implementation.
>> Source: https://github.com/notro/gud-pico
>>
>> +++ b/drivers/gpu/drm/gud/gud_drv.c
>> @@ -660,6 +660,7 @@ static int gud_resume(struct usb_interface *intf)
>>  
>>  static const struct usb_device_id gud_id_table[] = {
>>  	{ USB_DEVICE_INTERFACE_CLASS(0x1d50, 0x614d, USB_CLASS_VENDOR_SPEC) },
>> +	{ USB_DEVICE_INTERFACE_CLASS(0x16d0, 0x10a9, USB_CLASS_VENDOR_SPEC) },
>>  	{ }
>>  };
> 
> A VID/PID isn't neccessarily tied to one implementation; as long as an
> implementation is in fact compatible with the driver I consider it okay
> to reuse a VID/PID, and the 0x1d50 conditions are met by gud-pico too.
> That said, there's no harm in adding another id. :)
> 
> Reviewed-by: Peter Stuge <peter@stuge.se>
> 

Both patches applied, thanks for reviewing.

Noralf.