From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 057DBC88E53 for ; Tue, 15 Sep 2026 13:28:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=EcXSJVTvVZthIHGprEq2KGGmZzyD2tJp3Y6QBdt23ME=; b=o8whaF/VSyKR4LRa5fJVwg+MEn z0EXR5t0jUlhKXNPdEM0DJXnj8ThVG/07WRFbUN75NtScAqbhNDpOYNIkpRUkRSDqmpaP6toUgFxl ldv5wAEPIUNWX8KjDG/mwgKjIyf0HPFZ5cjs1V86UYLLd9TsYNfBQJj2SUYjZdLI9lxz59uWtLxx9 LfiCvvfaTINOHemCwgioullFKR36v0qVh0JVjLWhHJAnQADMOExTywOyYr4J1PVNkJLYzyZAl31IA 8cDWnpSjTKEyCfApKmFd1Jt+OtjPaDr35klrl4HTgSNV5Oz8hQgPN7tPxZnavxzE1M+RR0fbi20W3 wLl55rOg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6TCb-00000006jM5-22qI; Tue, 15 Sep 2026 13:28:01 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6TCa-00000006jLI-0LMC; Tue, 15 Sep 2026 13:28:00 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:Content-Type :In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date:Message-ID: Sender:Reply-To:Content-ID:Content-Description; bh=EcXSJVTvVZthIHGprEq2KGGmZzyD2tJp3Y6QBdt23ME=; b=k1R3ij4SeHdzW8BuCs6LfhL3qA pDQ0Voc80rCzBvC7GI/7mScndWx++2l0W+byAjNxS3US6NPh5iIazfsTBoiKLWBWPad5hilUnFUSb KBQ+U18aw/D7Nu+V1pQQvxa1L/NMIWcv4yfCwCO5VA994qW+zPNdgUGrhLPX1d2wjnUeTeDgRewXn nsuZibAOJwpuNzSVsBKCoFKvWVg40b3YI9JkNON1Q8c4IqFhhEWXSMUXURCNgsIXQd9RZOZ+DnBr0 xKG6gHfCpuLdBUHQw6inliUq6Tp7VAbvJP2U8KSuF2ZQeXQobSpEzOzCB6OiDlWBEuX0g29TaCSrL ygv/IkFA==; Received: from bali.collaboradmins.com ([148.251.105.195]) by desiato.infradead.org with esmtps (Exim 4.99.2 #2 (Red Hat Linux)) id 1x6TCV-00000006p4M-3gFk; Tue, 15 Sep 2026 13:27:58 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1789478873; bh=lohGgxfltMTEidmM0lOlsFdBrhEdgnJZYESmU16vlmQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=TWPA9Rt4P0ApNG8s1YVbxCYTY5s61WEx7UKrZaXAR7c4TsiqDLmjSAg/YM3x9/v8o 0xYKW2eshg4cNIBhUilWWQ1GxzkzOcbhKYh1UAXoz8OS+2vj4cnkErjHyD37FiRd0R 0Z7al0tPohX2G08Pnijxkrb5wIP0I4oepwnx+Fff8cobci6V4UuWQvhHHQ85aGUJDZ 7kkVDmVgT6/vaWcArKv2Du/KGbSg4GmE1T4eZlM4CoqwDVWtBsHxkfiX1T6bukXZLP VRXY3KSOJj2Bv5f6bOj7D229WMZ8043D+BhLZM642ZK+3r1EkJfPl3tDf2icaIVm2N f28gFzgSQV+Vg== Received: from [100.64.1.21] (unknown [100.64.1.21]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by bali.collaboradmins.com (Postfix) with ESMTPSA id 621B317E0082; Tue, 15 Sep 2026 15:27:53 +0200 (CEST) Message-ID: Date: Tue, 15 Sep 2026 15:27:52 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5] arm64: dts: mediatek: mt7986a-bananapi-bpi-r3: add ramoops region To: Martino Dell'Ambrogio , Matthias Brugger Cc: linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kees@kernel.org, tony.luck@intel.com, gpiccoli@igalia.com References: <20260915141226.600486-1-tillo@tillo.ch> From: AngeloGioacchino Del Regno Content-Language: en-US In-Reply-To: <20260915141226.600486-1-tillo@tillo.ch> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260915_142756_932434_A303E4EE X-CRM114-Status: GOOD ( 18.50 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On 9/15/26 14:12, Martino Dell'Ambrogio wrote: > Reserve 64 KiB of RAM just below the ARM Trusted Firmware secmon region > (0x42ff0000-0x43000000) for persistent kernel log storage via pstore/ramoops, > allowing post-panic console output and oops dumps to be recovered after a > warm reset. Without it, kernel crash logs on this board are lost when the > SoC reboots. > > The zone sizes (record-size=8 KiB, console-size=32 KiB, ftrace-size=8 KiB, > pmsg-size=8 KiB) consume the full 64 KiB carve-out. The requested ecc-size=16 > reserves a small Reed-Solomon parity block from each zone's own allocation > in persistent_ram_new(), which lets pstore recover dumps even when the panic > path truncates writes mid-record. > > The no-map property is required so the reserved region is kept out of the > kernel linear map. ramoops remaps the carve-out write-combine via > ioremap_wc(); on arm64, leaving the same physical RAM mapped cacheable in > the linear map at the same time is an attribute-mismatch and risks losing > panic data to dirty cache evictions from the linear alias. > > The region sits immediately below the ATF block already declared at > 0x43000000 in mt7986a.dtsi, so no other reserved-memory child is moved or > resized. BPI-R3 ships with 2 GiB of DRAM starting at 0x40000000, well above > 0x43000000, so the region is always within installed memory. > > For the carve-out to actually preserve content across a reset, the boot > loader must avoid touching this region on warm reset; on standard BPI-R3 > boards with the stock OpenWrt U-Boot fork this already holds. > > Signed-off-by: Martino Dell'Ambrogio > --- > Changes in v5: > - Restore this board's own carve-out. v4 carried the BPI-R4 values by > mistake - 1 MiB at 0x42f00000 with 128/256/64/64 KiB zones - while the > commit message still described the BPI-R3 layout. That would have reserved > 1 MiB instead of 64 KiB on a 2 GiB board and contradicted its own message. > Back to 64 KiB at 0x42ff0000 with 8/32/8/8 KiB, as in v3. Thanks to the > Sashiko review for catching it; entirely my error in regenerating the patch. > - No other change: the plain reserved-memory node from v4 is kept. > > The BPI-R4 patch is unaffected - its values were correct in v4 and it needs no > resend: > https://lore.kernel.org/all/20260915135722.566918-1-tillo@tillo.ch/ You forgot to send the 7988a bpi-r4 patch :-) Cheers, Angelo