> -----邮件原件----- > 发件人: Marek Vasut <[email protected]> > 发送时间: 2025年10月28日 22:39 > 收件人: Alice Guo (OSS) <[email protected]>; Marek Vasut > <[email protected]>; [email protected] > 抄送: Alice Guo <[email protected]>; Etienne Carriere > <[email protected]>; Patrick Delaunay > <[email protected]>; Peng Fan <[email protected]>; Tom Rini > <[email protected]>; Vinh Nguyen <[email protected]>; Viorel > Suman <[email protected]>; Ye Li <[email protected]> > 主题: Re: 回复: [PATCH] firmware: scmi: Drop > mmu_set_region_dcache_behaviour() misuse > > On 10/28/25 9:00 AM, Alice Guo (OSS) wrote: > >> -----邮件原件----- > >> 发件人: U-Boot <[email protected]> 代表 Marek Vasut > >> 发送时间: 2025年10月26日 5:35 > >> 收件人: [email protected] > >> 抄送: Marek Vasut <[email protected]>; Alice Guo > >> <[email protected]>; Etienne Carriere <[email protected]>; > >> Patrick Delaunay <[email protected]>; Peng Fan > >> <[email protected]>; Tom Rini <[email protected]>; Vinh Nguyen > >> <[email protected]>; Viorel Suman <[email protected]>; > Ye > >> Li <[email protected]> > >> 主题: [PATCH] firmware: scmi: Drop mmu_set_region_dcache_behaviour() > >> misuse > >> > >> MMU region cache behavior configuration for SCMI/SMT mailboxes is > >> platform specific. Even on ARM systems, the mailbox memory may not > >> even be located in any cacheable MMU region and may instead reside in > >> some SRAM. Remove this non-generic cache behavior configuration code > from generic code path. > >> > >> It is unlikely that any platform is affected by this change if it did > >> configure its MMU regions correctly on start up. Platforms which > >> might be affected are > >> i.MX94/95 and STM32MP. > >> > >> Fixes: 240720e9052f ("firmware: scmi: mailbox/smt agent device") > >> Fixes: 2a3f161c8b16 ("scmi: correctly configure MMU for SCMI buffer") > >> Fixes: b2ae10970d40 ("firmware: scmi: use PAGE_SIZE alignment for > >> ARM64") > >> Signed-off-by: Marek Vasut <[email protected]> > >> --- > >> Cc: Alice Guo <[email protected]> > >> Cc: Etienne Carriere <[email protected]> > >> Cc: Patrick Delaunay <[email protected]> > >> Cc: Peng Fan <[email protected]> > >> Cc: Tom Rini <[email protected]> > >> Cc: Vinh Nguyen <[email protected]> > >> Cc: Viorel Suman <[email protected]> > >> Cc: Ye Li <[email protected]> > >> Cc: [email protected] > >> --- > >> drivers/firmware/scmi/smt.c | 14 -------------- > >> 1 file changed, 14 deletions(-) > >> > >> diff --git a/drivers/firmware/scmi/smt.c > >> b/drivers/firmware/scmi/smt.c index > >> 237871559f0..cd1c0801f72 100644 > >> --- a/drivers/firmware/scmi/smt.c > >> +++ b/drivers/firmware/scmi/smt.c > >> @@ -61,20 +61,6 @@ int scmi_dt_get_smt_buffer(struct udevice *dev, > >> struct scmi_smt *smt) > >> if (device_is_compatible(dev, "arm,scmi") && > >> ofnode_has_property(dev_ofnode(dev), "mboxes")) > >> scmi_smt_enable_intr(smt, true); > >> > >> -#ifdef CONFIG_ARM > >> - if (dcache_status()) { > >> - u32 align_size; > >> - > >> - if (IS_ENABLED(CONFIG_ARM64)) > >> - align_size = PAGE_SIZE; > >> - else > >> - align_size = MMU_SECTION_SIZE; > >> - > >> - > >> mmu_set_region_dcache_behaviour(ALIGN_DOWN((uintptr_t)smt->buf, > >> align_size), > >> - ALIGN(smt->size, align_size), > >> DCACHE_OFF); > >> - } > >> -#endif > >> - > >> return 0; > >> } > >> > >> -- > >> 2.51.0 > > > > Tested-by: Alice Guo <[email protected]> > > > > Tested on two boards: IMX94 and IMX95. No regressions were observed > during boot. Looks good to me. > Thank you !
Hi Marek, Applied this patch on the U-Boot NXP tree and found that it affects the i.MX8ULP. On i.MX8ULP, the SCMI buffer is in SRAM and mapped as normal memory. U-Boot 2025.04-g26a24f1a2fe6-dirty (Oct 29 2025 - 18:07:13 +0800) M33 Sync: OK CPU: i.MX8ULP(Dual 7) rev1.1 at 800MHz CPU current temperature: 28 Reset cause: POR Boot mode: Single boot Model: NXP i.MX8ULP EVK DRAM: 2 GiB scmi-over-smccc scmi: Channel unexpectedly busy scmi_base_drv scmi-base.0: getting protocol version failed scmi-over-smccc scmi: failed to probe base protocol initcall failed at call 000000008022a890 (err=-16) ### ERROR ### Please RESET the board ### Best regards, Alice Guo
