On Tue, 2020-01-21 at 14:38 +0800, 王文虎 wrote: > 发件人：Scott Wood <o...@buserror.net> > 发送日期：2020-01-21 13:49:59 > 收件人："王文虎" <wenhu.w...@vivo.com> > 抄送人：wangwenhu <wenhu....@gmail.com>,Kumar Gala <ga...@kernel.crashing.org>,B > enjamin Herrenschmidt <b...@kernel.crashing.org>,Paul Mackerras < > pau...@samba.org>,Michael Ellerman <m...@ellerman.id.au>, > linuxppc-dev@lists.ozlabs.org,linux-ker...@vger.kernel.org, > triv...@kernel.org,Rai Harninder <harninder....@nxp.com> > 主题：Re: [PATCH] powerpc/Kconfig: Make FSL_85XX_CACHE_SRAM configurable>On > Tue, 2020-01-21 at 13:20 +0800, 王文虎 wrote: > > > From: Scott Wood <o...@buserror.net> > > > Date: 2020-01-21 11:25:25 > > > To: wangwenhu <wenhu....@gmail.com>,Kumar Gala < > > > ga...@kernel.crashing.org>, > > > Benjamin Herrenschmidt <b...@kernel.crashing.org>,Paul Mackerras < > > > pau...@samba.org>,Michael Ellerman <m...@ellerman.id.au>, > > > linuxppc-dev@lists.ozlabs.org,linux-ker...@vger.kernel.org > > > Cc: triv...@kernel.org,wenhu.w...@vivo.com,Rai Harninder < > > > harninder....@nxp.com> > > > Subject: Re: [PATCH] powerpc/Kconfig: Make FSL_85XX_CACHE_SRAM > > > configurable>On Mon, 2020-01-20 at 06:43 -0800, wangwenhu wrote: > > > > > From: wangwenhu <wenhu.w...@vivo.com> > > > > > > > > > > When generating .config file with menuconfig on Freescale BOOKE > > > > > SOC, FSL_85XX_CACHE_SRAM is not configurable for the lack of > > > > > description in the Kconfig field, which makes it impossible > > > > > to support L2Cache-Sram driver. Add a description to make it > > > > > configurable. > > > > > > > > > > Signed-off-by: wangwenhu <wenhu.w...@vivo.com> > > > > > > > > The intent was that drivers using the SRAM API would select the > > > > symbol. What > > > > is the use case for selecting it manually? > > > > > > > > > > With a repository of multiple products(meaning different defconfigs) and > > > multiple > > > developers, the Kconfigs of the Kernel Source Tree change frequently. So > > > the > > > "make menuconfig" > > > process is needed for defconfigs' re-generating or updating for the > > > complexity of dependencies > > > between different features defined in the Kconfigs. > > > > That doesn't answer my question of how the SRAM code would be useful other > > than to some other driver that uses the API (which would use > > "select"). There > > is no userspace API. You could use the kernel command line to configure > > the > > SRAM but you need to get the address of it for it to be useful. > > > > Like you've asked below, via /dev/mem or direct calling within the Kernel. > And they are not submitted yes, under development.
If they are calling within the kernel, then whatever driver that is should select FSL_85XX_CACHE_SRAM. Directly accessing /dev/mem without any way for the kernel to advertise where it is or which parts of SRAM are available for use sounds like a bad idea. -Scott
