Re: [PATCH] efifb: Ensure graphics device for efifb stays at PCI D0

From: Thomas Zimmermann
Date: Mon Feb 22 2021 - 03:08:54 EST


Hi

Am 22.02.21 um 08:08 schrieb Kai-Heng Feng:
On Mon, Feb 1, 2021 at 11:21 PM Alex Deucher <alexdeucher@xxxxxxxxx> wrote:

On Sat, Jan 30, 2021 at 6:27 AM Kai-Heng Feng
<kai.heng.feng@xxxxxxxxxxxxx> wrote:

We are seeing root ports on some desktop boards support D3cold for
discrete graphics card. So when efifb is in use while graphics device
isn't bound to a driver, PCI and ACPI will put the graphics to D3cold
when runtime suspend kicks in, makes efifb stop working.

So ensure the graphics device won't be runtime suspended, to keep efifb
work all the time.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>

Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>

A gentle ping...

Thanks for your patch. I've added it to drm-misc-next.

Best regards
Thomas



---
drivers/video/fbdev/efifb.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index e57c00824965..19edd7206409 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c
@@ -16,6 +16,7 @@
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/screen_info.h>
+#include <linux/pm_runtime.h>
#include <video/vga.h>
#include <asm/efi.h>
#include <drm/drm_utils.h> /* For drm_get_panel_orientation_quirk */
@@ -575,6 +576,7 @@ static int efifb_probe(struct platform_device *dev)
goto err_fb_dealoc;
}
fb_info(info, "%s frame buffer device\n", info->fix.id);
+ pm_runtime_get_sync(&efifb_pci_dev->dev);
return 0;

err_fb_dealoc:
@@ -601,6 +603,7 @@ static int efifb_remove(struct platform_device *pdev)
unregister_framebuffer(info);
sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
framebuffer_release(info);
+ pm_runtime_put(&efifb_pci_dev->dev);

return 0;
}
--
2.29.2

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--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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