From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B146819F40B; Sat, 6 Dec 2025 14:03:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765029803; cv=none; b=G9MoefA2IBaEiAfLjzqgYPDrMV4ZTohsenh3XiYk/r5sJQ0rMs98fv9D6jJY5cCtLOy2T6CavwKqU1NSlA07WEHt8TG4lY6bfecIT7yFIhoMNUOr3Cu5WLFqOsmwmirJ521ctJr8RdlhhYtNszbCdaIXJ1dTF5+ihHcYeJodazg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765029803; c=relaxed/simple; bh=DsxlSh+s7SLNpyrHOxgr0Wu9Nsi8eky7BBVL3tZ3kGo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UayflZp4i2Qs0k31nBs+W16m47TN/31jaiaTiVWfLrwFxRZ+Ey/BvNubhxHPI/rYPqT5kCB1HjtMBO8OK3h4elIJU14onHHX4XTI2PjSd74TutoLB+XPuNoMPEOoZQRMdN/0lLjGHrRoaUPxhRDF4MgEXaaT+Q1uvqRaf12AzN0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ostun3PS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ostun3PS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CDD6C113D0; Sat, 6 Dec 2025 14:03:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765029803; bh=DsxlSh+s7SLNpyrHOxgr0Wu9Nsi8eky7BBVL3tZ3kGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ostun3PSIp4Ribej8A7pc4dYYTswFnMKcn0//OyTnHprlAqGYdKrDKJ18ojbodSUt S2a5Rn0EQCUN42B3ckcaB8/biQ20cXSZ8JW4WU/rT+4+STvhBy7aqcA5D3+Vli4buD bp/XxnuKSMIVI7ogTuKjknAoOw4Kyfx/avP8p0KiSz9CT19D9Qygbp7hExViOGhlrF 3U3BWHf2Kuu6Se3/KhmIDPLNbb/BCKwqHmR8fi5lxH740vzX5eoFqi6q6bMwMkoSo4 Ac3gwWqTgihFwVVmacQ9y6Xq3x0GlWUnVKteavxL5GmHgKTzP0x1CDlcrTHXR01RIF AdniueqBQ37zw== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Hans de Goede , Arend van Spriel , Johannes Berg , Sasha Levin , alexandre.f.demers@gmail.com, alexander.deucher@amd.com Subject: [PATCH AUTOSEL 6.18-6.1] wifi: brcmfmac: Add DMI nvram filename quirk for Acer A1 840 tablet Date: Sat, 6 Dec 2025 09:02:18 -0500 Message-ID: <20251206140252.645973-13-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251206140252.645973-1-sashal@kernel.org> References: <20251206140252.645973-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.18 Content-Transfer-Encoding: 8bit From: Hans de Goede [ Upstream commit a8e5a110c0c38e08e5dd66356cd1156e91cf88e1 ] The Acer A1 840 tablet contains quite generic names in the sys_vendor and product_name DMI strings, without this patch brcmfmac will try to load: brcmfmac43340-sdio.Insyde-BayTrail.txt as nvram file which is a bit too generic. Add a DMI quirk so that a unique and clearly identifiable nvram file name is used on the Acer A1 840 tablet. Acked-by: Arend van Spriel Signed-off-by: Hans de Goede Link: https://patch.msgid.link/20251103100314.353826-1-hansg@kernel.org Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: ## Analysis of Commit for Stable Backporting ### 1. COMMIT MESSAGE ANALYSIS **Subject:** wifi: brcmfmac: Add DMI nvram filename quirk for Acer A1 840 tablet **Key observations:** - No `Cc: stable@vger.kernel.org` tag present - No `Fixes:` tag pointing to a prior commit - The commit explains that the tablet has generic DMI strings ("Insyde" / "BayTrail") - Without the patch, brcmfmac loads `brcmfmac43340-sdio.Insyde- BayTrail.txt` which is "a bit too generic" The wording "a bit too generic" suggests this is more of an improvement/optimization rather than fixing broken functionality. ### 2. CODE CHANGE ANALYSIS The change adds: 1. A new `brcmf_dmi_data` structure: ```c static const struct brcmf_dmi_data acer_a1_840_data = { BRCM_CC_43340_CHIP_ID, 2, "acer-a1-840" }; ``` 2. A DMI match entry with three match criteria (vendor, product, BIOS date) to identify this specific tablet and associate it with the new data structure. **Technical nature:** Pure data addition - adds static const data and a DMI table entry using existing infrastructure. ### 3. CLASSIFICATION This is a **hardware quirk** for DMI-based nvram filename selection. Hardware quirks are generally allowable in stable per the documented exceptions. ### 4. SCOPE AND RISK ASSESSMENT - **Size:** ~15 lines added, very small - **Files:** Single file (dmi.c) - **Risk:** Extremely low - only affects the specific Acer A1 840 tablet - **Pattern:** Follows identical pattern to ~15 other existing DMI quirks in this file ### 5. USER IMPACT - **Who is affected:** Only Acer Iconia One 8 A1-840 tablet owners - **Severity:** The commit message says the generic filename is "a bit too generic" - not that WiFi is broken - **Nature:** This enables using a device-specific nvram file instead of a generic one ### 6. STABILITY INDICATORS - Acked by Broadcom maintainer (Arend van Spriel) - Hans de Goede is well-known for x86 tablet quirks - No explicit stable request from maintainers ### 7. DEPENDENCY CHECK - Requires corresponding `brcmfmac43340-sdio.acer-a1-840.txt` file in linux-firmware - No code dependencies on other kernel commits - DMI quirk infrastructure exists in all stable trees ### Decision Rationale **Arguments for backporting:** - Falls under "hardware quirks" exception - Zero risk to other systems - Small, contained change - Uses existing infrastructure **Arguments against backporting:** 1. **No stable tags:** The maintainers did not add `Cc: stable@vger.kernel.org`, suggesting they don't consider this critical for stable 2. **Not fixing broken functionality:** The commit says the generic name is "a bit too generic" - not that WiFi doesn't work. This is an improvement, not a fix for completely broken hardware 3. **Firmware dependency:** Requires a corresponding nvram file in linux-firmware that may not be present in stable distributions 4. **Enablement vs Fix:** This is adding device-specific customization rather than fixing a bug. The generic nvram file path still works, just isn't optimally specific 5. **No reported bug:** No `Reported-by:` tag or link to a bug report indicating users are affected ### Conclusion While hardware quirks are sometimes appropriate for stable, this particular quirk is more of an enhancement to use a more specific nvram filename rather than a fix for broken functionality. The maintainer's decision not to add stable tags, combined with the "a bit too generic" language (rather than "doesn't work"), indicates this is a quality-of- life improvement rather than a critical fix. Stable trees should focus on fixes for actual broken functionality, not optimizations for firmware filename selection. **NO** .../net/wireless/broadcom/brcm80211/brcmfmac/dmi.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/dmi.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/dmi.c index c3a602197662b..abe7f6501e5ed 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/dmi.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/dmi.c @@ -24,6 +24,10 @@ static const struct brcmf_dmi_data acepc_t8_data = { BRCM_CC_4345_CHIP_ID, 6, "acepc-t8" }; +static const struct brcmf_dmi_data acer_a1_840_data = { + BRCM_CC_43340_CHIP_ID, 2, "acer-a1-840" +}; + /* The Chuwi Hi8 Pro uses the same Ampak AP6212 module as the Chuwi Vi8 Plus * and the nvram for the Vi8 Plus is already in linux-firmware, so use that. */ @@ -91,6 +95,16 @@ static const struct dmi_system_id dmi_platform_data[] = { }, .driver_data = (void *)&acepc_t8_data, }, + { + /* Acer Iconia One 8 A1-840 (non FHD version) */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Insyde"), + DMI_MATCH(DMI_PRODUCT_NAME, "BayTrail"), + /* Above strings are too generic also match BIOS date */ + DMI_MATCH(DMI_BIOS_DATE, "04/01/2014"), + }, + .driver_data = (void *)&acer_a1_840_data, + }, { /* Chuwi Hi8 Pro with D2D3_Hi8Pro.233 BIOS */ .matches = { -- 2.51.0