| Message ID | 20170111133357.3664191-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jan 11, 2017 at 02:33:34PM +0100, Arnd Bergmann wrote: > When building DRM without an MMU, we run into a compile-time error because > pte_wrprotect() is not defined: > > drivers/gpu/drm/drm_vm.c: In function 'drm_mmap_dma': > drivers/gpu/drm/drm_vm.c:496:9: error: implicit declaration of function 'pte_wrprotect' [-Werror=implicit-function-declaration] > > The line is not meaningful here, so we can simply add another > compile-time check around it. > > Fixes: 62a0d98a188c ("drm: allow to use mmuless SoC") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> We don't need drm_vm.c on modern drivers, and the idea was to simply not compile it when not needed. See: commit 99c48e1e38f0aeaa107ad67c8d91f6c9d9d567a9 Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> Date: Wed Jan 4 10:12:56 2017 +0100 drm: compile drm_vm.c only when needed How did you manage to enable this stuff? -Daniel > --- > drivers/gpu/drm/drm_vm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c > index bd311c77c254..038946588ed7 100644 > --- a/drivers/gpu/drm/drm_vm.c > +++ b/drivers/gpu/drm/drm_vm.c > @@ -488,7 +488,7 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma) > vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); > #if defined(__i386__) || defined(__x86_64__) > pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; > -#else > +#elif IS_ENABLED(CONFIG_MMU) > /* Ye gads this is ugly. With more thought > we could move this up higher and use > `protection_map' instead. */ > @@ -572,7 +572,7 @@ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma) > vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); > #if defined(__i386__) || defined(__x86_64__) > pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; > -#else > +#elif defined (CONFIG_MMU) > /* Ye gads this is ugly. With more thought > we could move this up higher and use > `protection_map' instead. */ > -- > 2.9.0 >
On Wednesday, January 11, 2017 5:27:13 PM CET Daniel Vetter wrote: > On Wed, Jan 11, 2017 at 02:33:34PM +0100, Arnd Bergmann wrote: > > When building DRM without an MMU, we run into a compile-time error because > > pte_wrprotect() is not defined: > > > > drivers/gpu/drm/drm_vm.c: In function 'drm_mmap_dma': > > drivers/gpu/drm/drm_vm.c:496:9: error: implicit declaration of function 'pte_wrprotect' [-Werror=implicit-function-declaration] > > > > The line is not meaningful here, so we can simply add another > > compile-time check around it. > > > > Fixes: 62a0d98a188c ("drm: allow to use mmuless SoC") > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > We don't need drm_vm.c on modern drivers, and the idea was to simply not > compile it when not needed. See: > > commit 99c48e1e38f0aeaa107ad67c8d91f6c9d9d567a9 > Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> > Date: Wed Jan 4 10:12:56 2017 +0100 > > drm: compile drm_vm.c only when needed > > > How did you manage to enable this stuff? > -Daniel This was a randconfig build, the DRM specific symbols here are CONFIG_DRM=y CONFIG_DRM_MIPI_DSI=y # CONFIG_DRM_DP_AUX_CHARDEV is not set # CONFIG_DRM_DEBUG_MM is not set # CONFIG_DRM_DEBUG_MM_SELFTEST is not set CONFIG_DRM_KMS_HELPER=y CONFIG_DRM_KMS_FB_HELPER=y # CONFIG_DRM_FBDEV_EMULATION is not set CONFIG_DRM_LOAD_EDID_FIRMWARE=y CONFIG_DRM_GEM_CMA_HELPER=y CONFIG_DRM_KMS_CMA_HELPER=y CONFIG_DRM_VM=y # # I2C encoder or helper chips # # CONFIG_DRM_I2C_CH7006 is not set CONFIG_DRM_I2C_SIL164=y # CONFIG_DRM_I2C_NXP_TDA998X is not set CONFIG_DRM_ARM=y CONFIG_DRM_HDLCD=y CONFIG_DRM_HDLCD_SHOW_UNDERRUN=y # CONFIG_DRM_MALI_DISPLAY is not set # # ACP (Audio CoProcessor) Configuration # CONFIG_DRM_VGEM=y CONFIG_DRM_ROCKCHIP=y CONFIG_ROCKCHIP_ANALOGIX_DP=y CONFIG_ROCKCHIP_DW_HDMI=m CONFIG_ROCKCHIP_DW_MIPI_DSI=y CONFIG_ROCKCHIP_INNO_HDMI=m # CONFIG_DRM_UDL is not set CONFIG_DRM_ARMADA=y CONFIG_DRM_ATMEL_HLCDC=m CONFIG_DRM_RCAR_DU=y # CONFIG_DRM_RCAR_HDMI is not set CONFIG_DRM_RCAR_LVDS=y # CONFIG_DRM_SHMOBILE is not set CONFIG_DRM_SUN4I=y CONFIG_DRM_TILCDC=m CONFIG_DRM_TILCDC_SLAVE_COMPAT=y CONFIG_DRM_MSM=y CONFIG_DRM_MSM_REGISTER_LOGGING=y CONFIG_DRM_MSM_HDMI_HDCP=y CONFIG_DRM_MSM_DSI=y # CONFIG_DRM_MSM_DSI_PLL is not set # CONFIG_DRM_MSM_DSI_28NM_PHY is not set # CONFIG_DRM_MSM_DSI_20NM_PHY is not set CONFIG_DRM_MSM_DSI_28NM_8960_PHY=y # CONFIG_DRM_FSL_DCU is not set # CONFIG_DRM_TEGRA is not set CONFIG_DRM_PANEL=y # # Display Panels # CONFIG_DRM_PANEL_SIMPLE=m CONFIG_DRM_PANEL_JDI_LT070ME05000=m CONFIG_DRM_PANEL_PANASONIC_VVX10F034N00=m # CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0 is not set # CONFIG_DRM_PANEL_SHARP_LQ101R1SX01 is not set # CONFIG_DRM_PANEL_SHARP_LS043T1LE01 is not set CONFIG_DRM_BRIDGE=y # # Display Interface Bridges # CONFIG_DRM_ANALOGIX_ANX78XX=y CONFIG_DRM_DUMB_VGA_DAC=m CONFIG_DRM_DW_HDMI=m CONFIG_DRM_DW_HDMI_AHB_AUDIO=m # CONFIG_DRM_NXP_PTN3460 is not set CONFIG_DRM_PARADE_PS8622=m # CONFIG_DRM_SIL_SII8620 is not set # CONFIG_DRM_SII902X is not set # CONFIG_DRM_TOSHIBA_TC358767 is not set CONFIG_DRM_TI_TFP410=y CONFIG_DRM_ANALOGIX_DP=y # CONFIG_DRM_I2C_ADV7511 is not set CONFIG_DRM_VC4=m CONFIG_DRM_ETNAVIV=m # CONFIG_DRM_ETNAVIV_REGISTER_LOGGING is not set CONFIG_DRM_ARCPGU=m CONFIG_DRM_MXS=y CONFIG_DRM_MXSFB=m CONFIG_DRM_MESON=y CONFIG_DRM_LEGACY=y # CONFIG_DRM_LIB_RANDOM is not set No idea what did it in the end. I also have some older build fixes applied, so it may be something that happens on my tree but not on plain linux-next. Arnd
On Wed, Jan 11, 2017 at 5:33 PM, Arnd Bergmann <arnd@arndb.de> wrote: > On Wednesday, January 11, 2017 5:27:13 PM CET Daniel Vetter wrote: >> On Wed, Jan 11, 2017 at 02:33:34PM +0100, Arnd Bergmann wrote: >> > When building DRM without an MMU, we run into a compile-time error because >> > pte_wrprotect() is not defined: >> > >> > drivers/gpu/drm/drm_vm.c: In function 'drm_mmap_dma': >> > drivers/gpu/drm/drm_vm.c:496:9: error: implicit declaration of function 'pte_wrprotect' [-Werror=implicit-function-declaration] >> > >> > The line is not meaningful here, so we can simply add another >> > compile-time check around it. >> > >> > Fixes: 62a0d98a188c ("drm: allow to use mmuless SoC") >> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> >> >> We don't need drm_vm.c on modern drivers, and the idea was to simply not >> compile it when not needed. See: >> >> commit 99c48e1e38f0aeaa107ad67c8d91f6c9d9d567a9 >> Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> >> Date: Wed Jan 4 10:12:56 2017 +0100 >> >> drm: compile drm_vm.c only when needed >> >> >> How did you manage to enable this stuff? >> -Daniel > > This was a randconfig build, the DRM specific symbols here are > > CONFIG_DRM=y > CONFIG_DRM_MIPI_DSI=y > # CONFIG_DRM_DP_AUX_CHARDEV is not set > # CONFIG_DRM_DEBUG_MM is not set > # CONFIG_DRM_DEBUG_MM_SELFTEST is not set > CONFIG_DRM_KMS_HELPER=y > CONFIG_DRM_KMS_FB_HELPER=y > # CONFIG_DRM_FBDEV_EMULATION is not set > CONFIG_DRM_LOAD_EDID_FIRMWARE=y > CONFIG_DRM_GEM_CMA_HELPER=y > CONFIG_DRM_KMS_CMA_HELPER=y > CONFIG_DRM_VM=y Does randconfig just set this for fun, despite that it's a hidden Kconfig symbol? Should we add a depends !NOMMU to it to make sure it never gets enabled when it shouldn't be? tbh I have no idea how Kconfig works, I'm just really good at breaking it :( -Daniel
On Wed, Jan 11, 2017 at 5:36 PM, Daniel Vetter <daniel@ffwll.ch> wrote: > On Wed, Jan 11, 2017 at 5:33 PM, Arnd Bergmann <arnd@arndb.de> wrote: >> CONFIG_DRM_VM=y > > Does randconfig just set this for fun, despite that it's a hidden > Kconfig symbol? Should we add a depends !NOMMU to it to make sure it > never gets enabled when it shouldn't be? > > tbh I have no idea how Kconfig works, I'm just really good at breaking it :( no, randconfig won't try to set symbols that a user doesn't see. This is what 'menuconfig' says enabled it. │ Selected by: DRM_NOUVEAU [=n] && HAS_IOMEM [=y] && DRM [=y] && PCI [=n] && MMU [=n] && (BACKLIGHT_CLASS_DEVICE [=m] || !ACPI) || DRM_LEGACY [=y] && HAS_IOMEM [=y] && DRM [=y] It must be the 'DRM_LEGACY' option that is actually user visible and that contains 'select DRM_VM'. Arnd
2017-01-11 17:59 GMT+01:00 Arnd Bergmann <arnd@arndb.de>: > On Wed, Jan 11, 2017 at 5:36 PM, Daniel Vetter <daniel@ffwll.ch> wrote: >> On Wed, Jan 11, 2017 at 5:33 PM, Arnd Bergmann <arnd@arndb.de> wrote: >>> CONFIG_DRM_VM=y >> >> Does randconfig just set this for fun, despite that it's a hidden >> Kconfig symbol? Should we add a depends !NOMMU to it to make sure it >> never gets enabled when it shouldn't be? >> >> tbh I have no idea how Kconfig works, I'm just really good at breaking it :( > > no, randconfig won't try to set symbols that a user doesn't see. This > is what 'menuconfig' > says enabled it. > > │ Selected by: DRM_NOUVEAU [=n] && HAS_IOMEM [=y] && DRM [=y] && > PCI [=n] && MMU [=n] && (BACKLIGHT_CLASS_DEVICE [=m] || !ACPI) || > DRM_LEGACY [=y] && HAS_IOMEM [=y] && DRM [=y] > > It must be the 'DRM_LEGACY' option that is actually user visible and > that contains > 'select DRM_VM'. We should add "MMU" on DRM_LEGACY and DRM_VM dependencies to be sure that they won't be select without MMU support > > Arnd
diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c index bd311c77c254..038946588ed7 100644 --- a/drivers/gpu/drm/drm_vm.c +++ b/drivers/gpu/drm/drm_vm.c @@ -488,7 +488,7 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma) vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); #if defined(__i386__) || defined(__x86_64__) pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; -#else +#elif IS_ENABLED(CONFIG_MMU) /* Ye gads this is ugly. With more thought we could move this up higher and use `protection_map' instead. */ @@ -572,7 +572,7 @@ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma) vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); #if defined(__i386__) || defined(__x86_64__) pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; -#else +#elif defined (CONFIG_MMU) /* Ye gads this is ugly. With more thought we could move this up higher and use `protection_map' instead. */
When building DRM without an MMU, we run into a compile-time error because pte_wrprotect() is not defined: drivers/gpu/drm/drm_vm.c: In function 'drm_mmap_dma': drivers/gpu/drm/drm_vm.c:496:9: error: implicit declaration of function 'pte_wrprotect' [-Werror=implicit-function-declaration] The line is not meaningful here, so we can simply add another compile-time check around it. Fixes: 62a0d98a188c ("drm: allow to use mmuless SoC") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/gpu/drm/drm_vm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)