[Intel-gfx] [PATCH 3/3] drm/i915: Do not disable cxsr when crtc is disabled.

[Ville Syrjälä]

On Wed, Feb 03, 2016 at 04:53:25PM +0100, Maarten Lankhorst wrote:
> It's safe to assume cxsr is already disabled when the crtc is off.

Hmm. Yeah, looks like that's how we set it up currently. I thought we
might leave it on with 0 active pipes, but I guess not.

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> This prevents an unclaimed register warning when the required power
> wells are not enabled.
> 
> [  262.864984] ------------[ cut here ]------------
> [  262.865025] WARNING: CPU: 1 PID: 6799 at drivers/gpu/drm/i915/intel_uncore.c:638 __unclaimed_reg_debug+0x68/0x80 [i915]()
> [  262.865029] Unclaimed register detected before reading register 0x186500
> [  262.865032] Modules linked in: i915 intel_powerclamp
> [  262.865057] CPU: 1 PID: 6799 Comm: kms_pipe_crc_ba Tainted: G     U  W       4.4.0-gfxbench+ #1
> [  262.865060] Hardware name: DN2820FYK, BIOS FYBYT10H.86A.0038.2014.0717.1455 07/17/2014
> [  262.865064]  ffffffffa0338cf8 ffff88007448ba78 ffffffff813df90c ffff88007448bac0
> [  262.865071]  ffff88007448bab0 ffffffff810746e1 0000000000186500 0000000000000001
> [  262.865077]  0000000000000001 ffff880074420000 0000000000000000 ffff88007448bb10
> [  262.865083] Call Trace:
> [  262.865092]  [<ffffffff813df90c>] dump_stack+0x4e/0x82
> [  262.865098]  [<ffffffff810746e1>] warn_slowpath_common+0x81/0xc0
> [  262.865102]  [<ffffffff81074767>] warn_slowpath_fmt+0x47/0x50
> [  262.865128]  [<ffffffffa02a07e8>] __unclaimed_reg_debug+0x68/0x80 [i915]
> [  262.865154]  [<ffffffffa02a0e4e>] vlv_read32+0x2de/0x370 [i915]
> [  262.865173]  [<ffffffffa0256837>] intel_set_memory_cxsr+0x87/0x1a0 [i915]
> [  262.865200]  [<ffffffffa02c4cb3>] intel_pre_plane_update+0xb3/0xf0 [i915]
> [  262.865228]  [<ffffffffa02c54b5>] intel_atomic_commit+0x3b5/0x17c0 [i915]
> [  262.865234]  [<ffffffff8150dc45>] ? drm_atomic_check_only+0x145/0x660
> [  262.865239]  [<ffffffff8150d75a>] ? drm_atomic_set_crtc_for_connector+0x6a/0xe0
> [  262.865243]  [<ffffffff8150e192>] drm_atomic_commit+0x32/0x50
> [  262.865249]  [<ffffffff814eb155>] drm_atomic_helper_set_config+0x75/0xb0
> [  262.865253]  [<ffffffff814fd090>] drm_mode_set_config_internal+0x60/0x110
> [  262.865258]  [<ffffffff81501e26>] drm_mode_setcrtc+0x186/0x4f0
> [  262.865263]  [<ffffffff814f3eed>] drm_ioctl+0x13d/0x590
> [  262.865267]  [<ffffffff81501ca0>] ? drm_mode_setplane+0x1b0/0x1b0
> [  262.865273]  [<ffffffff811d4c4c>] do_vfs_ioctl+0x2fc/0x550
> [  262.865278]  [<ffffffff8118d5ea>] ? vm_munmap+0x4a/0x60
> [  262.865283]  [<ffffffff811e06ba>] ? __fget_light+0x6a/0x90
> [  262.865287]  [<ffffffff811d4edc>] SyS_ioctl+0x3c/0x70
> [  262.865292]  [<ffffffff8179a75b>] entry_SYSCALL_64_fastpath+0x16/0x73
> [  262.865296] ---[ end trace 6387a0ad001bb39f ]---
> 
> Testcase: kms_flip.basic-flip-vs-wf_vblank
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93698
> 
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index c7f2a18ab34e..4fcbdd6037a4 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4837,7 +4837,9 @@ static void intel_pre_plane_update(struct intel_crtc_state *old_crtc_state)
>  
>  	if (pipe_config->disable_cxsr) {
>  		crtc->wm.cxsr_allowed = false;
> -		intel_set_memory_cxsr(dev_priv, false);
> +
> +		if (old_crtc_state->base.active)
> +			intel_set_memory_cxsr(dev_priv, false);
>  	}
>  
>  	if (!needs_modeset(&pipe_config->base) && pipe_config->wm_changed)
> -- 
> 2.1.0
> 
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-- 
Ville Syrjälä
Intel OTC