From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
Signed-off-by: Vivek Das Mohapatra vivek@collabora.com Signed-off-by: Emil Velikov emil.velikov@collabora.com --- Greetings all,
This patch has been downstream for a while now yet it seems perfectly reasonable thing to have in the Linux kernel.
https://github.com/ValveSoftware/steamos_kernel/commit/5431b5b1999c3d3b5efee...
drivers/gpu/drm/i915/display/intel_vga.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c index be333699c515..4f07b5ad5fa0 100644 --- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -30,12 +30,14 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) u8 sr1;
/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */ - vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); - outb(SR01, VGA_SR_INDEX); - sr1 = inb(VGA_SR_DATA); - outb(sr1 | 1 << 5, VGA_SR_DATA); - vga_put(pdev, VGA_RSRC_LEGACY_IO); - udelay(300); + if (pdev == vga_default_device()) { + vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); + outb(SR01, VGA_SR_INDEX); + sr1 = inb(VGA_SR_DATA); + outb(sr1 | 1 << 5, VGA_SR_DATA); + vga_put(pdev, VGA_RSRC_LEGACY_IO); + udelay(300); + }
intel_de_write(dev_priv, vga_reg, VGA_DISP_DISABLE); intel_de_posting_read(dev_priv, vga_reg);
On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote:
From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Signed-off-by: Vivek Das Mohapatra vivek@collabora.com Signed-off-by: Emil Velikov emil.velikov@collabora.com
Greetings all,
This patch has been downstream for a while now yet it seems perfectly reasonable thing to have in the Linux kernel.
https://github.com/ValveSoftware/steamos_kernel/commit/5431b5b1999c3d3b5efee...
drivers/gpu/drm/i915/display/intel_vga.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c index be333699c515..4f07b5ad5fa0 100644 --- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -30,12 +30,14 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) u8 sr1;
/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */
- vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
- outb(SR01, VGA_SR_INDEX);
- sr1 = inb(VGA_SR_DATA);
- outb(sr1 | 1 << 5, VGA_SR_DATA);
- vga_put(pdev, VGA_RSRC_LEGACY_IO);
- udelay(300);
if (pdev == vga_default_device()) {
vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);outb(SR01, VGA_SR_INDEX);sr1 = inb(VGA_SR_DATA);outb(sr1 | 1 << 5, VGA_SR_DATA);vga_put(pdev, VGA_RSRC_LEGACY_IO);udelay(300);}
intel_de_write(dev_priv, vga_reg, VGA_DISP_DISABLE); intel_de_posting_read(dev_priv, vga_reg);
-- 2.27.0
Hi Ville,
On Mon, 17 May 2021 at 18:24, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote:
From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Bunch of context is lost due to the patch age, so I'm not 100% sure of the actual hardware setup where this occurs. Does the following make sense?
Currently on dual GPU systems, we do not get seamless handover as the output flickers during the transition bootloader -> plymouth -> desktop. This happens as a result of switching (via the VGA arbiter) from the "other" GPU back to the default i915 one and issuing io() commands.
-Emil
On Tue, May 18, 2021 at 12:09:56PM +0100, Emil Velikov wrote:
Hi Ville,
On Mon, 17 May 2021 at 18:24, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote:
From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Bunch of context is lost due to the patch age, so I'm not 100% sure of the actual hardware setup where this occurs. Does the following make sense?
Currently on dual GPU systems, we do not get seamless handover as the output flickers during the transition bootloader -> plymouth -> desktop. This happens as a result of switching (via the VGA arbiter) from the "other" GPU back to the default i915 one and issuing io() commands.
Hmm. Does this work?
--- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -29,6 +29,9 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); u8 sr1;
+ if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE) + return; + /* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */ vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); outb(SR01, VGA_SR_INDEX);
On Tue, 18 May 2021 at 12:17, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Tue, May 18, 2021 at 12:09:56PM +0100, Emil Velikov wrote:
Hi Ville,
On Mon, 17 May 2021 at 18:24, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote:
From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Bunch of context is lost due to the patch age, so I'm not 100% sure of the actual hardware setup where this occurs. Does the following make sense?
Currently on dual GPU systems, we do not get seamless handover as the output flickers during the transition bootloader -> plymouth -> desktop. This happens as a result of switching (via the VGA arbiter) from the "other" GPU back to the default i915 one and issuing io() commands.
Hmm. Does this work?
Thanks I'll it give it a try. Might need a few days to find the right hardware/software combination.
-Emil
Hi Ville,
On Tue, 18 May 2021 at 12:17, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Tue, May 18, 2021 at 12:09:56PM +0100, Emil Velikov wrote:
Hi Ville,
On Mon, 17 May 2021 at 18:24, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote:
From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Bunch of context is lost due to the patch age, so I'm not 100% sure of the actual hardware setup where this occurs. Does the following make sense?
Currently on dual GPU systems, we do not get seamless handover as the output flickers during the transition bootloader -> plymouth -> desktop. This happens as a result of switching (via the VGA arbiter) from the "other" GPU back to the default i915 one and issuing io() commands.
Hmm. Does this work?
--- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -29,6 +29,9 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); u8 sr1;
if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)return;/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */ vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); outb(SR01, VGA_SR_INDEX);
Was able to replicate the issue somewhat and the above does help quite a lot. Feel free to add my: Reviewed-by: Emil Velikov emil.velikov@collabora.com Tested-by: Emil Velikov emil.velikov@collabora.com
Also feel free to reuse as much/little of the following setup details.
To reproduce the issue:
Get a dual GPU system - Intel+Nvidia in my case. Set the other (Nvidia) as default in UEFI and connect monitors to it. Ensure the bootloader (and if using splash manager like plymouth) are set to display the UEFI BGRT. Personally I tested systemd-boot, although GRUB should also work. I couldn't get plymouth to work/behave here :shrug:
Note: Having the Nvidia drivers in the initramfs can lead to extra flicker so leave them out. Include the i915 drivers in initramfs.
Without the patch, the existing bootslash is wiped clean almost instantaneously as the i915 driver calls intel_vga_disable(). With your patch the call is a no-op, and the bootsplash stays around until the login manager (and X) is spawned.
HTH Emil
On Wed, 26 May 2021 at 17:21, Emil Velikov emil.l.velikov@gmail.com wrote:
Hi Ville,
On Tue, 18 May 2021 at 12:17, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Tue, May 18, 2021 at 12:09:56PM +0100, Emil Velikov wrote:
Hi Ville,
On Mon, 17 May 2021 at 18:24, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote:
From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Bunch of context is lost due to the patch age, so I'm not 100% sure of the actual hardware setup where this occurs. Does the following make sense?
Currently on dual GPU systems, we do not get seamless handover as the output flickers during the transition bootloader -> plymouth -> desktop. This happens as a result of switching (via the VGA arbiter) from the "other" GPU back to the default i915 one and issuing io() commands.
Hmm. Does this work?
--- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -29,6 +29,9 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); u8 sr1;
if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)return;/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */ vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); outb(SR01, VGA_SR_INDEX);Was able to replicate the issue somewhat and the above does help quite a lot. Feel free to add my: Reviewed-by: Emil Velikov emil.velikov@collabora.com Tested-by: Emil Velikov emil.velikov@collabora.com
Humble poke.
Cannot see this patch in the drm-misc or drm-intel trees. Is there anything I do to help move it forward?
Thanks -Emil
On Fri, Jun 04, 2021 at 02:47:16PM +0100, Emil Velikov wrote:
On Wed, 26 May 2021 at 17:21, Emil Velikov emil.l.velikov@gmail.com wrote:
Hi Ville,
On Tue, 18 May 2021 at 12:17, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Tue, May 18, 2021 at 12:09:56PM +0100, Emil Velikov wrote:
Hi Ville,
On Mon, 17 May 2021 at 18:24, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote:
From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Bunch of context is lost due to the patch age, so I'm not 100% sure of the actual hardware setup where this occurs. Does the following make sense?
Currently on dual GPU systems, we do not get seamless handover as the output flickers during the transition bootloader -> plymouth -> desktop. This happens as a result of switching (via the VGA arbiter) from the "other" GPU back to the default i915 one and issuing io() commands.
Hmm. Does this work?
--- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -29,6 +29,9 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); u8 sr1;
if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)return;/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */ vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); outb(SR01, VGA_SR_INDEX);Was able to replicate the issue somewhat and the above does help quite a lot. Feel free to add my: Reviewed-by: Emil Velikov emil.velikov@collabora.com Tested-by: Emil Velikov emil.velikov@collabora.com
Humble poke.
Cannot see this patch in the drm-misc or drm-intel trees. Is there anything I do to help move it forward?
Can you just respin the patch with this?
On Fri, 4 Jun 2021 at 15:08, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Fri, Jun 04, 2021 at 02:47:16PM +0100, Emil Velikov wrote:
On Wed, 26 May 2021 at 17:21, Emil Velikov emil.l.velikov@gmail.com wrote:
Hi Ville,
On Tue, 18 May 2021 at 12:17, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Tue, May 18, 2021 at 12:09:56PM +0100, Emil Velikov wrote:
Hi Ville,
On Mon, 17 May 2021 at 18:24, Ville Syrjälä ville.syrjala@linux.intel.com wrote:
On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote: > From: Vivek Das Mohapatra vivek@collabora.com > > This patch is to do with seamless handover, eg when the sequence is > bootloader → plymouth → desktop. > > It switches the vga arbiter from the "other" GPU to the default one > (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Bunch of context is lost due to the patch age, so I'm not 100% sure of the actual hardware setup where this occurs. Does the following make sense?
Currently on dual GPU systems, we do not get seamless handover as the output flickers during the transition bootloader -> plymouth -> desktop. This happens as a result of switching (via the VGA arbiter) from the "other" GPU back to the default i915 one and issuing io() commands.
Hmm. Does this work?
--- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -29,6 +29,9 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); u8 sr1;
if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE)return;/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */ vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); outb(SR01, VGA_SR_INDEX);Was able to replicate the issue somewhat and the above does help quite a lot. Feel free to add my: Reviewed-by: Emil Velikov emil.velikov@collabora.com Tested-by: Emil Velikov emil.velikov@collabora.com
Humble poke.
Cannot see this patch in the drm-misc or drm-intel trees. Is there anything I do to help move it forward?
Can you just respin the patch with this?
I've used your suggestion and redone the commit message completely. Hope it's far less cryptic now. Patch is on the ML - realised I didn't CC you, just as it went out.
https://lore.kernel.org/dri-devel/20210604154905.660142-1-emil.l.velikov@gma...
Thanks -Emil
dri-devel@lists.freedesktop.org
-
Emil Velikov -
Ville Syrjälä