From: "Luis R. Rodriguez" mcgrof@do-not-panic.com
Commit 3cf2667 as of next-20130301 extended the struct fb_info with a skip_vt_switch to allow drivers to skip the VT switch at suspend/resume time. For older kernels we can skip this as all this switch does is call pm_vt_switch_required() with true or false depending on this new flag and later pm_vt_switch_unregister() would not have been made.
This patch cannot be broken down further so I'm pegging this as the first one with 4 digits under the DRM folder for collateral evolutions. This reflects its as atomic as is possible. As we'll see on the next commit, these type of collateral evolutions can best be backported not by keeping ifdef's as below but instead by using a wrapper caller, to help reduce with the amount of lines of code we need. If a static inline is added upstream for these changes, then no code is required for backporting, at all, we'd just implement the static inline later upstream as a no-op.
The tradeoffs to consider for this is if we can live with these practices upstream, we may be able to support full subsystems only with a compat module, and no need for patches. This also means less code and likely less bugs on the distribution front when backporting is required. At least IMHO this may be worthy to consider at least to support kernels listed as supported on kernel.org. We could just leave the ifdef hell to older unsupported kernels.
Relevant commits below, starting with the first one that added this new collateral evolution.
commit 3cf2667b9f8b2c2fe298a427deb399e52321da6b Author: Jesse Barnes jbarnes@virtuousgeek.org Date: Mon Feb 4 13:37:21 2013 +0000
fb: add support for drivers not needing VT switch at suspend/resume time
Use the new PM routines to indicate whether we need to VT switch at suspend and resume time. When a new driver is bound, set its flag accordingly, and when unbound, remove it from the PM's console tracking list.
Signed-off-by: Jesse Barnes jbarnes@virtuousgeek.org Acked-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch
commit 24576d23976746cb52e7700c4cadbf4bc1bc3472 Author: Jesse Barnes jbarnes@virtuousgeek.org Date: Tue Mar 26 09:25:45 2013 -0700
drm/i915: enable VT switchless resume v3
With the other bits in place, we can do this safely.
v2: disable backlight on suspend to prevent premature enablement on resume v3: disable CRTCs on suspend to allow RTD3 (Kristen)
Signed-off-by: Jesse Barnes jbarnes@virtuousgeek.org Reviewed-by: Rodrigo Vivi rodrigo.vivi@gmail.com Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch
Cc: cocci@systeme.lip6.fr Cc: backports@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Julia Lawall julia.lawall@lip6.fr Cc: Rodrigo Vivi rodrigo.vivi@gmail.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Jesse Barnes jbarnes@virtuousgeek.org Cc: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Luis R. Rodriguez mcgrof@do-not-panic.com --- .../drm/0001-fb-info-vt_switch.patch | 73 ++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 patches/collateral-evolutions/drm/0001-fb-info-vt_switch.patch
diff --git a/patches/collateral-evolutions/drm/0001-fb-info-vt_switch.patch b/patches/collateral-evolutions/drm/0001-fb-info-vt_switch.patch new file mode 100644 index 0000000..cdced87 --- /dev/null +++ b/patches/collateral-evolutions/drm/0001-fb-info-vt_switch.patch @@ -0,0 +1,73 @@ +Commit 3cf2667 as of next-20130301 extended the struct fb_info +with a skip_vt_switch to allow drivers to skip the VT switch +at suspend/resume time. For older kernels we can skip this +as all this switch does is call pm_vt_switch_required() with true +or false depending on this new flag and later +pm_vt_switch_unregister() would not have been made. + +This patch cannot be broken down further so I'm pegging +this as the first one with 4 digits under the DRM folder +for collateral evolutions. This reflects its as atomic as +is possible. As we'll see on the next commit, these type +of collateral evolutions can best be backported not by +keeping ifdef's as below but instead by using a wrapper +caller, to help reduce with the amount of lines of code +we need. If a static inline is added upstream for these +changes, then no code is required for backporting, at all, +we'd just implement the static inline later upstream as +a no-op. + +The tradeoffs to consider for this is if we can live with +these practices upstream, we may be able to support full +subsystems only with a compat module, and no need for +patches. This also means less code and likely less bugs +on the distribution front when backporting is required. +At least IMHO this may be worthy to consider at least to +support kernels listed as supported on kernel.org. We could +just leave the ifdef hell to older unsupported kernels. + +Relevant commits below, starting with the first one that +added this new collateral evolution. + +commit 3cf2667b9f8b2c2fe298a427deb399e52321da6b +Author: Jesse Barnes jbarnes@virtuousgeek.org +Date: Mon Feb 4 13:37:21 2013 +0000 + + fb: add support for drivers not needing VT switch at suspend/resume time + + Use the new PM routines to indicate whether we need to VT switch at suspend + and resume time. When a new driver is bound, set its flag accordingly, + and when unbound, remove it from the PM's console tracking list. + + Signed-off-by: Jesse Barnes jbarnes@virtuousgeek.org + Acked-by: Rafael J. Wysocki rafael.j.wysocki@intel.com + Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch + +commit 24576d23976746cb52e7700c4cadbf4bc1bc3472 +Author: Jesse Barnes jbarnes@virtuousgeek.org +Date: Tue Mar 26 09:25:45 2013 -0700 + + drm/i915: enable VT switchless resume v3 + + With the other bits in place, we can do this safely. + + v2: disable backlight on suspend to prevent premature enablement on resume + v3: disable CRTCs on suspend to allow RTD3 (Kristen) + + Signed-off-by: Jesse Barnes jbarnes@virtuousgeek.org + Reviewed-by: Rodrigo Vivi rodrigo.vivi@gmail.com + Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch + +--- a/drivers/gpu/drm/i915/intel_fb.c ++++ b/drivers/gpu/drm/i915/intel_fb.c +@@ -150,8 +150,10 @@ static int intelfb_create(struct drm_fb_ + } + info->screen_size = size; + ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)) + /* This driver doesn't need a VT switch to restore the mode on resume */ + info->skip_vt_switch = true; ++#endif + + drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth); + drm_fb_helper_fill_var(info, &ifbdev->helper, sizes->fb_width, sizes->fb_height);