On Mon, 26 Jun 2023 10:00:09 +0100, "Lim, Jit Loon" jit.loon.lim@intel.com wrote:
-----Original Message----- From: Marek Vasut marex@denx.de Sent: Wednesday, 21 June, 2023 10:20 PM To: Marc Zyngier maz@kernel.org; Lim, Jit Loon jit.loon.lim@intel.com Cc: u-boot@lists.denx.de; Jagan Teki jagan@amarulasolutions.com; Simon simon.k.r.goldschmidt@gmail.com; Chee, Tien Fong tien.fong.chee@intel.com; Hea, Kok Kiang kok.kiang.hea@intel.com; Lokanathan, Raaj raaj.lokanathan@intel.com; Maniyam, Dinesh dinesh.maniyam@intel.com; Ng, Boon Khai boon.khai.ng@intel.com; Yuslaimi, Alif Zakuan alif.zakuan.yuslaimi@intel.com; Chong, Teik Heng teik.heng.chong@intel.com; Zamri, Muhammad Hazim Izzat muhammad.hazim.izzat.zamri@intel.com; Tang, Sieu Mun sieu.mun.tang@intel.com; Ying-Chun Liu paul.liu@linaro.org; Lee, Kah Jing kah.jing.lee@intel.com Subject: Re: [PATCH v1] cache_v8: agilex5: Disable Dcache in the SPL
On 6/21/23 16:15, Marc Zyngier wrote:
On Wed, 21 Jun 2023 15:06:51 +0100, Jit Loon Lim jit.loon.lim@intel.com wrote:
From: Kah Jing Lee kah.jing.lee@intel.com
Dcache feature is not enabled in SPL and enable it will cause ISR exception. Since the Dcache is not supported in SPL, new CONFIG_SPL_SYS_DISABLE_DCACHE_OPS is added to Kconfig to disable Dcache in SPL.
Signed-off-by: Kah Jing Lee kah.jing.lee@intel.com
This is missing your own SoB.
Now, I'd like to understand what you are actually trying to fix. What is this 'ISR' exception? This isn't something the architecture describes. Unless you are using CMOs on something that isn't memory or for which you don't have a mapping, this should never generate an exception.
You beat me to it, indeed, thanks !
The intention of doing this is because when we init SDMMC driver, the driver will call the invalidate_dcache_range. However, during that time, the dcache is not available in SPL yet thus causing exception.
Again: which exception?
There is no such thing as "the dcache isn't available". It is always valid to invalidate it, irrespective of it being enabled or not.
My impression is that you are papering over another bug (such as feeding non-memory to the CMOs), and are getting an SError back, which would be entirely justified.
M.