RE: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu
Russell, Thanks for your comments. Thank you, Best regards, Hari > -Original Message- > From: Russell King - ARM Linux [mailto:li...@arm.linux.org.uk] > Sent: Wednesday, August 05, 2009 3:23 PM > To: Kanigeri, Hari > Cc: Hiroshi DOYU; linux-omap@vger.kernel.org; t...@atomide.com; Shilimkar, > Santosh > Subject: Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for > omap4 iommu > > On Wed, Aug 05, 2009 at 11:44:53AM -0500, Kanigeri, Hari wrote: > > -- I agree with your comments from OMAP3 point of view. > > For OMAP4, I guess Camera is not going to use IOMMU module. IOMMU > > modules will be used only by the IPC that are communicating with 2 > > remote Cores (Ducati and Tesla). > > In which case what you do is: > > config OMAP_CAMERA > ... > select OMAP_IOMMU if ARCH_OMAP3 > > which means the IOMMU support will only be built if the camera is enabled > and we're building for OMAP3. > > However, if the OMAP3 hardware uses the IOMMU but the OMAP4 hardware > doesn't, I'd hazard a guess (and it's only a guess) that the drivers > will be soo different that squeezing them into one file/config option > would be silly. > > > Having said this, there might not > > be any clients of IOMMU in the Kernel space as we are looking at > > the option of using the IOMMU as a character driver from User-space. > > For this reason, I think we should have the configuration option to > > build iommu. Please let me know your comments. > > In which case, the IOMMU character driver can select the core IOMMU > support. > > Making symbols which are 'selected' visible causes problems - you > can't disable them and you can't work out why they're being > forcefully enabled, which just annoys people who are trying to > configure the kernel. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu
On Wed, Aug 05, 2009 at 11:44:53AM -0500, Kanigeri, Hari wrote: > -- I agree with your comments from OMAP3 point of view. > For OMAP4, I guess Camera is not going to use IOMMU module. IOMMU > modules will be used only by the IPC that are communicating with 2 > remote Cores (Ducati and Tesla). In which case what you do is: config OMAP_CAMERA ... select OMAP_IOMMU if ARCH_OMAP3 which means the IOMMU support will only be built if the camera is enabled and we're building for OMAP3. However, if the OMAP3 hardware uses the IOMMU but the OMAP4 hardware doesn't, I'd hazard a guess (and it's only a guess) that the drivers will be soo different that squeezing them into one file/config option would be silly. > Having said this, there might not > be any clients of IOMMU in the Kernel space as we are looking at > the option of using the IOMMU as a character driver from User-space. > For this reason, I think we should have the configuration option to > build iommu. Please let me know your comments. In which case, the IOMMU character driver can select the core IOMMU support. Making symbols which are 'selected' visible causes problems - you can't disable them and you can't work out why they're being forcefully enabled, which just annoys people who are trying to configure the kernel. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu
Hi Russell and Hiroshi, Thanks for your comments. Please see my below comments. > -Original Message- > From: Hiroshi DOYU [mailto:hiroshi.d...@nokia.com] > Sent: Tuesday, August 04, 2009 11:36 PM > To: Kanigeri, Hari > Cc: linux-omap@vger.kernel.org; t...@atomide.com; li...@arm.linux.org.uk; > Shilimkar, Santosh > Subject: Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for > omap4 iommu > > From: ext Russell King - ARM Linux > Subject: Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for > omap4 iommu > Date: Wed, 5 Aug 2009 00:42:41 +0200 > > > On Tue, Aug 04, 2009 at 05:32:12PM -0500, Kanigeri, Hari wrote: > > > diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig > > > index efe85d0..50aaefb 100644 > > > --- a/arch/arm/plat-omap/Kconfig > > > +++ b/arch/arm/plat-omap/Kconfig > > > @@ -118,8 +118,11 @@ config OMAP_MBOX_FWK > > > DSP, IVA1.0 and IVA2 in OMAP1/2/3. > > > > > > config OMAP_IOMMU > > > - tristate > > > - > > > + tristate "iommu" > > > > Insufficiently verbose description. "OMAP IOMMU Support" would be > > better. I thought the idea here was to arrange for things to select > > OMAP_IOMMU when they require it rather than offering it as a separate > > configuration option. > > > > The former way has the advantage that you don't need to know that you > > need IOMMU support to (eg) use the Camera - enabling the Camera > > should automatically enable IOMMU support. > > The following is the original discussion. > > http://lists.arm.linux.org.uk/lurker/message/20090518.130233.3f238e72.en.h > tml -- I agree with your comments from OMAP3 point of view. For OMAP4, I guess Camera is not going to use IOMMU module. IOMMU modules will be used only by the IPC that are communicating with 2 remote Cores (Ducati and Tesla). Having said this, there might not be any clients of IOMMU in the Kernel space as we are looking at the option of using the IOMMU as a character driver from User-space. For this reason, I think we should have the configuration option to build iommu. Please let me know your comments. Thank you, Best regards, Hari -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu
From: ext Russell King - ARM Linux Subject: Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu Date: Wed, 5 Aug 2009 09:52:20 +0200 > On Wed, Aug 05, 2009 at 07:35:38AM +0300, Hiroshi DOYU wrote: > > From: ext Russell King - ARM Linux > > Subject: Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 > > iommu > > Date: Wed, 5 Aug 2009 00:42:41 +0200 > > > > > On Tue, Aug 04, 2009 at 05:32:12PM -0500, Kanigeri, Hari wrote: > > > > diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig > > > > index efe85d0..50aaefb 100644 > > > > --- a/arch/arm/plat-omap/Kconfig > > > > +++ b/arch/arm/plat-omap/Kconfig > > > > @@ -118,8 +118,11 @@ config OMAP_MBOX_FWK > > > > DSP, IVA1.0 and IVA2 in OMAP1/2/3. > > > > > > > > config OMAP_IOMMU > > > > - tristate > > > > - > > > > + tristate "iommu" > > > > > > Insufficiently verbose description. "OMAP IOMMU Support" would be > > > better. I thought the idea here was to arrange for things to select > > > OMAP_IOMMU when they require it rather than offering it as a separate > > > configuration option. > > > > > > The former way has the advantage that you don't need to know that you > > > need IOMMU support to (eg) use the Camera - enabling the Camera > > > should automatically enable IOMMU support. > > > > The following is the original discussion. > > > > http://lists.arm.linux.org.uk/lurker/message/20090518.130233.3f238e72.en.html > > Quite. I'm repeating myself. So the question is why the original > discussion didn't produce a change. The original discussion was applied and can be kept for OMAP4 as well like: config SOME_NEW_DEVICE_USE_IOMMU ... select OMAP_IOMMU ... Just setting the above select line would be ok. For example, http://marc.info/?l=linux-omap&m=124867965731465&w=2 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu
On Wed, Aug 05, 2009 at 07:35:38AM +0300, Hiroshi DOYU wrote: > From: ext Russell King - ARM Linux > Subject: Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 > iommu > Date: Wed, 5 Aug 2009 00:42:41 +0200 > > > On Tue, Aug 04, 2009 at 05:32:12PM -0500, Kanigeri, Hari wrote: > > > diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig > > > index efe85d0..50aaefb 100644 > > > --- a/arch/arm/plat-omap/Kconfig > > > +++ b/arch/arm/plat-omap/Kconfig > > > @@ -118,8 +118,11 @@ config OMAP_MBOX_FWK > > > DSP, IVA1.0 and IVA2 in OMAP1/2/3. > > > > > > config OMAP_IOMMU > > > - tristate > > > - > > > + tristate "iommu" > > > > Insufficiently verbose description. "OMAP IOMMU Support" would be > > better. I thought the idea here was to arrange for things to select > > OMAP_IOMMU when they require it rather than offering it as a separate > > configuration option. > > > > The former way has the advantage that you don't need to know that you > > need IOMMU support to (eg) use the Camera - enabling the Camera > > should automatically enable IOMMU support. > > The following is the original discussion. > > http://lists.arm.linux.org.uk/lurker/message/20090518.130233.3f238e72.en.html Quite. I'm repeating myself. So the question is why the original discussion didn't produce a change. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu
From: ext Russell King - ARM Linux Subject: Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu Date: Wed, 5 Aug 2009 00:42:41 +0200 > On Tue, Aug 04, 2009 at 05:32:12PM -0500, Kanigeri, Hari wrote: > > diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig > > index efe85d0..50aaefb 100644 > > --- a/arch/arm/plat-omap/Kconfig > > +++ b/arch/arm/plat-omap/Kconfig > > @@ -118,8 +118,11 @@ config OMAP_MBOX_FWK > > DSP, IVA1.0 and IVA2 in OMAP1/2/3. > > > > config OMAP_IOMMU > > - tristate > > - > > + tristate "iommu" > > Insufficiently verbose description. "OMAP IOMMU Support" would be > better. I thought the idea here was to arrange for things to select > OMAP_IOMMU when they require it rather than offering it as a separate > configuration option. > > The former way has the advantage that you don't need to know that you > need IOMMU support to (eg) use the Camera - enabling the Camera > should automatically enable IOMMU support. The following is the original discussion. http://lists.arm.linux.org.uk/lurker/message/20090518.130233.3f238e72.en.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v1 3/3] ARM:OMAP4 iommu:provide build support for omap4 iommu
On Tue, Aug 04, 2009 at 05:32:12PM -0500, Kanigeri, Hari wrote: > diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig > index efe85d0..50aaefb 100644 > --- a/arch/arm/plat-omap/Kconfig > +++ b/arch/arm/plat-omap/Kconfig > @@ -118,8 +118,11 @@ config OMAP_MBOX_FWK > DSP, IVA1.0 and IVA2 in OMAP1/2/3. > > config OMAP_IOMMU > - tristate > - > + tristate "iommu" Insufficiently verbose description. "OMAP IOMMU Support" would be better. I thought the idea here was to arrange for things to select OMAP_IOMMU when they require it rather than offering it as a separate configuration option. The former way has the advantage that you don't need to know that you need IOMMU support to (eg) use the Camera - enabling the Camera should automatically enable IOMMU support. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
