| Message ID | 20140520111525.3a62e25d@endymion.delvare (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 20, 2014 at 11:15:25AM +0200, Jean Delvare wrote: > The following configuration options combination: > > CONFIG_DRM_EXYNOS_DP=y > CONFIG_DRM_PTN3460=m > > currently leads to the following linker failure: > > drivers/built-in.o: In function `exynos_drm_attach_lcd_bridge': > .../drivers/gpu/drm/exynos/exynos_dp_core.c:1004: > undefined reference to `ptn3460_init' > > This is because ptn3460_init can't be implemented in a module while > its caller is built into the kernel. So add the proper dependency in > Kconfig so that the above can't happen. > > I moved DRM_PTN3460 earlier in Kconfig, next to the I2C helper module > section, so that the user has a chance to select it before moving to > the Exynos-specific section. > > IMHO the proper way to solve the problem would be to turn ptn3460 into > a clean I2C driver, similar to the other I2C helper chip drivers. It's > the only way to not sink into impossible-to-guess dependencies. Then > ptn3460 could even be moved together with the other I2C helper chip > drivers. FWIW, various ideas have been discussed to solve this problem. The most recent agreement I think was to create a registry for bridge drivers to register DRM bridge objects against and allow drivers to look them up. That way we can get rid of the various *_init() functions that currently need to be called directly from within DRM drivers. I'm not aware of anybody working on this currently, hence I think this is an appropriate fix in the meantime: Reviewed-by: Thierry Reding <treding@nvidia.com>
On 2014? 05? 22? 00:51, Thierry Reding wrote: > On Tue, May 20, 2014 at 11:15:25AM +0200, Jean Delvare wrote: >> The following configuration options combination: >> >> CONFIG_DRM_EXYNOS_DP=y >> CONFIG_DRM_PTN3460=m >> >> currently leads to the following linker failure: >> >> drivers/built-in.o: In function `exynos_drm_attach_lcd_bridge': >> .../drivers/gpu/drm/exynos/exynos_dp_core.c:1004: >> undefined reference to `ptn3460_init' >> >> This is because ptn3460_init can't be implemented in a module while >> its caller is built into the kernel. So add the proper dependency in >> Kconfig so that the above can't happen. >> >> I moved DRM_PTN3460 earlier in Kconfig, next to the I2C helper module >> section, so that the user has a chance to select it before moving to >> the Exynos-specific section. >> >> IMHO the proper way to solve the problem would be to turn ptn3460 into >> a clean I2C driver, similar to the other I2C helper chip drivers. It's >> the only way to not sink into impossible-to-guess dependencies. Then >> ptn3460 could even be moved together with the other I2C helper chip >> drivers. > > FWIW, various ideas have been discussed to solve this problem. The most > recent agreement I think was to create a registry for bridge drivers to > register DRM bridge objects against and allow drivers to look them up. > That way we can get rid of the various *_init() functions that currently > need to be called directly from within DRM drivers. > I tend to prefer integrated drm_bridge based on drm_panel infrastructure so that bridge drivers can use Linux driver-model. But it seems not easy to reach a consensus on it. picked it up. Thanks, Inki Dae > I'm not aware of anybody working on this currently, hence I think this > is an appropriate fix in the meantime: > > Reviewed-by: Thierry Reding <treding@nvidia.com> > > > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel >
--- linux-3.15-rc5.orig/drivers/gpu/drm/Kconfig 2014-04-14 09:42:29.689070224 +0200 +++ linux-3.15-rc5/drivers/gpu/drm/Kconfig 2014-05-19 14:47:02.872050099 +0200 @@ -83,6 +83,8 @@ config DRM_KMS_CMA_HELPER source "drivers/gpu/drm/i2c/Kconfig" +source "drivers/gpu/drm/bridge/Kconfig" + config DRM_TDFX tristate "3dfx Banshee/Voodoo3+" depends on DRM && PCI @@ -199,5 +201,3 @@ source "drivers/gpu/drm/msm/Kconfig" source "drivers/gpu/drm/tegra/Kconfig" source "drivers/gpu/drm/panel/Kconfig" - -source "drivers/gpu/drm/bridge/Kconfig" --- linux-3.15-rc5.orig/drivers/gpu/drm/exynos/Kconfig 2014-04-14 09:42:29.698070438 +0200 +++ linux-3.15-rc5/drivers/gpu/drm/exynos/Kconfig 2014-05-19 15:23:18.867919528 +0200 @@ -50,7 +50,7 @@ config DRM_EXYNOS_DSI config DRM_EXYNOS_DP bool "EXYNOS DRM DP driver support" - depends on DRM_EXYNOS && ARCH_EXYNOS + depends on DRM_EXYNOS && ARCH_EXYNOS && (DRM_PTN3460=n || DRM_PTN3460=y || DRM_PTN3460=DRM_EXYNOS) default DRM_EXYNOS help This enables support for DP device.
The following configuration options combination: CONFIG_DRM_EXYNOS_DP=y CONFIG_DRM_PTN3460=m currently leads to the following linker failure: drivers/built-in.o: In function `exynos_drm_attach_lcd_bridge': .../drivers/gpu/drm/exynos/exynos_dp_core.c:1004: undefined reference to `ptn3460_init' This is because ptn3460_init can't be implemented in a module while its caller is built into the kernel. So add the proper dependency in Kconfig so that the above can't happen. I moved DRM_PTN3460 earlier in Kconfig, next to the I2C helper module section, so that the user has a chance to select it before moving to the Exynos-specific section. IMHO the proper way to solve the problem would be to turn ptn3460 into a clean I2C driver, similar to the other I2C helper chip drivers. It's the only way to not sink into impossible-to-guess dependencies. Then ptn3460 could even be moved together with the other I2C helper chip drivers. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: David Airlie <airlied@linux.ie> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: Seung-Woo Kim <sw0312.kim@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Kukjin Kim <kgene.kim@samsung.com> --- drivers/gpu/drm/Kconfig | 4 ++-- drivers/gpu/drm/exynos/Kconfig | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-)