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 CBF453DEAD2; Mon, 10 Aug 2026 13:04:38 +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=1786367078; cv=none; b=TctEv3D96X6fd8BIb115Exw1jqPr5G0MhoY4xRw8MHaG/kuLMnLX2NoMY1vykKvJFOQ+HgoilxIzHrXbcgwLjU71oddJPfzNm3tYT+2oIhObjefrcWiMcziz//j7BA03xKTc3tQKm6mWZ2kHpMN5rC0todrkC5DfTxcN6iQ7FVQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786367078; c=relaxed/simple; bh=VleUTPyNYCta8Pce//26vwcSESLQGjcQbaTRoUUxTl4=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=orKTY3RRU854TSK+RIB1m1jAHtBfkyJl+kIp8Okm97CK9uXUOz4eAPw3Z2aermdLxLEwf6uxZuOdcycSiSXPfQodGkEnSb4cKbBpeEIWfC0kt3D5qDRHIKkWzalXDyiyrRc0U1Bj4XKdqUAyBFFUBLX3p2P6ywLV7eanGu4sFvs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NS6VELix; 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="NS6VELix" Received: by smtp.kernel.org (Postfix) with ESMTPS id 2A1C7C19425; Mon, 10 Aug 2026 13:04:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1786367078; bh=VleUTPyNYCta8Pce//26vwcSESLQGjcQbaTRoUUxTl4=; h=From:Subject:Date:To:Cc:Reply-To:From; b=NS6VELixcJ8nNmMdclWWATvrKvK0bfDHK4Kqzy9tW4JhOJVFLDtN6VuFG0qjW6JLl V4tWzTJVJQ9iTzQpd7B/pw78eokn2serKlZvZWreNs3h9QOvwU3WUDoWkO4i766LFE qmgH9JQnPwLsryk5MIF4aB3s57H1TIt1H1Q/pTlAHmMx8KwiOZb4AW3X2nYfRCSaw+ NcweGYbMDo8NnB6jBKZcTyLn1RRUGTHgzCSN0BZnkaHom6/SfkUDSdJzEcfyOmCt5f FyUpw4/ydTb7hL9DPfHuydNo8Wr7JSwoUf4y8DndtriB+yLDHCt1P51yx17A2hZvgd IBIZSJB55t2Ug== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05575C5AE49; Mon, 10 Aug 2026 13:04:38 +0000 (UTC) From: Miao Wang via B4 Relay Subject: [PATCH RFC v8 0/8] mfd: ls2kbmc: multiple fixes for this driver Date: Mon, 10 Aug 2026 21:04:23 +0800 Message-Id: <20260810-ls2kbmc-mod-v8-0-16e44f7322f4@gmail.com> Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAFjMeWoC/33Pz0rEMBAG8FdZcjYymSSTxJMg+ABexUP+7ga3W 2mlKEvf3diLbRc8zgy/b/iubMxDzSN7OFzZkKc61v7SBnt3YPHkL8fMa2ozQ0ACQuLnEd9DF3n XJ64RnHASwAVkTXwMudSvJe2VvTw/sbe2PNXxsx++lw+TWE5LmAG7CZsEBx6lUqHolIuXj8fO1 /N97LslZ8J/LDaLvqQkjBKGaG/lygrYWtlsLkZYkpSNzXurVlaKrVXNJgShAYNH6fZW/1kLamv 1718KUceUnHc3fWlt9dZSs4JiTFkJTPamr1nZfV/TrPUeStBeK8K1nef5BzfUTJQTAgAA X-Change-ID: 20260626-ls2kbmc-mod-5209193009b2 To: Binbin Zhou , Chong Qiao , Lee Jones , Huacai Chen , Corey Minyard , Linus Walleij , Bartosz Golaszewski Cc: Xi Ruoyao , WANG Xuerui , Yinbo Zhu , Jiaxun Yang , mfd@lists.linux.dev, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, openipmi-developer@lists.sourceforge.net, Miao Wang , Corey Minyard X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=6101; i=shankerwangmiao@gmail.com; s=20250715; h=from:subject:message-id; bh=VleUTPyNYCta8Pce//26vwcSESLQGjcQbaTRoUUxTl4=; b=owEBbQKS/ZANAwAKAbAx48p7/tluAcsmYgBqecxbsFXRzpbvqkkSfXdU6rnlNHSDi93mAs+Te QTi1ljvV9uJAjMEAAEKAB0WIQREqPWPgPJBxluezBOwMePKe/7ZbgUCannMWwAKCRCwMePKe/7Z bggwEACGOo3k5L5/Dmpq58mkv3y8dd0tlm6p/6r1BO3K062Igkf1K8d/bPsfaNsmJnuEPs0DIjM Og8d6cSaloHpAznoxXSv5T76tkvszAAdZ60FhGLgQ/1y+SRzgzhySs2IqJpJgG3l5n7ZBjPrbHj uj6VU9nJr6FQoXu7inIeKu/jlOiz0S5wXn/Z4r6FWQgtRSJa1TxhMOFO7js+VOq7+7fTjnx9O8A 3iIuZkafEjlJlSQJ5ukVQWPvMg+z23rKmtDMuPsV8cul6yZK7S9McA81USfYml1sslg3pQ5IpQ1 lLeSSi455mcuCIQoyDFd6oGmwRlgiQrtgl+PqTRxjmrttDXY/15RinsE9oFlIYqLD7E464R9X78 tTMjzxl/3vsLDw3rwKd6VVW+UQXNb4Vf2Rhr8Hhly32uoIKh+RPAvzAqGVybz4g4VR/Ac1XM+FF B7ybBcgvhJ7UROI0/iqUQ4rTiGLkctNRfs8fsFgic91JhlGrkFJrJZRS7V+epInjqMqFQiB004P BPUv4TYJn8Z0aThK2Bw9jDkbEwiHDvblbq9lS4RiXXZkPtll80OMSwlznafaCp2rl6jMuz9tF9p hppA1Dkd6llBR8tyuwzmNBGaTsVFdDRRSdVyBeXt7X5PC87cBo5jYpfX/BFQxoj0v/hp4m9qkuw sbDsnvc5bmd8prQ== X-Developer-Key: i=shankerwangmiao@gmail.com; a=openpgp; fpr=6FAEFF06B7D212A774C60BFDFA0D166D6632EF4A X-Endpoint-Received: by B4 Relay for shankerwangmiao@gmail.com/20250715 with auth_id=462 X-Original-From: Miao Wang Reply-To: shankerwangmiao@gmail.com Previously, the driver has been introduced to support the Loongson 2K BMC running on the Loongson Servers, which is essential to prevent the system from hanging when the BMC is being reset and the default efi-framebuffer is being used. However, there are some drawbacks in the driver. Firstly, the driver tries to read and write to the connected PCI-E host controller registers, assuming that the BMC is connected to LS7A PCI-E host controller. This assumption should be true for real products, but to prevent from accidentally reading and writing to the wrong PCI-E host controller, this driver should be modified to check this before accessing the registers. Secondly, the driver uses non-exported functions to tell the vt subsystem to redraw the screen, preventing the driver from being compiling as a module. This can be fixed by using the exported functions instead. Thirdly, the driver directly accesses the GPIO controller registers using hard-coded addresses, which might conflict with the loaded GPIO controller driver for the same GPIO controller. This is fixed in this series by using the GPIO subsystem APIs instead. To associate a GPIO pin with a certian PCI device, it should be declared in the firmware level, i.e. in the ACPI table or the device tree, and thus the firmware interface should be discussed and coordinated with Loongson personnels. Despite of this, the proposed solution in this series should be the minimum necessary change to express such association. Furthermore, the conventional GPIO pin number and the controller address are also provided, to be used as a fallback when the GPIO pin is not declared. Finally, there is a minor issue in the driver where it changes the mode string describing the screen resolution during probing, which prevents the device from being probed again if -EPROBE_DEFER is returned by the probe function. I have tested the changes in this series on a single-socket Loongson 3C6000 server with a Loongson 2K BMC, and the driver works as expected when the corresponding GPIO driver is additionally loaded. Signed-off-by: Miao Wang --- Changes in v8: - Address issues found by the Sashiko AI review bot - Fix the error path of the probe function, preventing unintentionally returning 0 on failure - Reorder the patches in the series to make the change to the Kconfig entry for ls2kbmc to be the last patch, to satisfy the AI bot's concern on failure to clean up when the driver is built as a module and is being removed. - Link to v7: https://lore.kernel.org/r/20260810-ls2kbmc-mod-v7-0-8aa0fb5a5462@gmail.com Changes in v7: - When parsing the mode string, require the mode string to start with "video=", reverting the change in v5. Add a comment to describe the reason for this change to satisfy the AI bot's concern. - When printing the invalid mode string, use %*pE to print the string to prevent the string from printing garbage characters, as suggested by the AI bot. - When calculating the stride, check that the multiplication of width and depth does not overflow, as suggested by the AI bot. - Add gpio_device_get_fwnode() into gpiolib.c as a library function to get the fwnode of a GPIO device, as suggested by Bartosz. - Adjust the coding style of the patch as suggested by Bartosz. - Link to v6: https://lore.kernel.org/r/20260805-ls2kbmc-mod-v6-0-16ccde412d86@gmail.com Changes in v6: - Ajdust the Kconfig entry for IPMI_LS2K, moving the dependency on MFD_LS2K_BMC_CORE to the IPMI_SI Kconfig entry, as discussed with and agreed by Corey. - Link to v5: https://lore.kernel.org/r/20260804-ls2kbmc-mod-v5-0-e6bc5cdd9a93@gmail.com Changes in v5: - Address issues found by the Sashiko AI review bot - Maintain the compatibility with possible unexpected mode string when parsing, although such mode string is actually not expected, to satisfy the AI bot's concern. - Add a comment to point out that the adjustment of the Kconfig entry for ls2kbmc is in the following patch, to satisfy the AI bot's concern. - Link to v4: https://lore.kernel.org/r/20260731-ls2kbmc-mod-v4-0-d201502ba239@gmail.com Changes in v4: - Use a better way to get the GPIO device fwnode. - Add a comment to describe a problem found by AI bot which is actually intended. - Link to v3: https://lore.kernel.org/r/20260710-ls2kbmc-mod-v3-0-ef718636e78e@gmail.com Changes in v3: - Check the return value of devm_add_action_or_reset when registering the cleanup hook of the work queue - Use swnode to create the link between the device to the GPIO chip, and prevent borrowing the legacy GPIO APIs - Link to v2: https://lore.kernel.org/r/20260708-ls2kbmc-mod-v2-0-2afdd1741766@gmail.com Changes in v2: - Several fixes suggested by the Sashiko AI review bot - Add a cleanup function for the wq on removal of the device - Relax the reverse dependency from CONFIG_IPMI_LS2K to CONFIG_MFD_LS2K_BMC_CORE to allow the driver to be built as a module - Link to v1: https://lore.kernel.org/r/20260708-ls2kbmc-mod-v1-0-c344bf5defa3@gmail.com --- Miao Wang (8): mfd: ls2kbmc: Make a copy when parsing mode string mfd: ls2kbmc: Sanity check for the connected pci port mfd: ls2kbmc: Redraw using exported functions mfd: ls2kbmc: Cancel the work queue on removal ipmi: ls2k: adjust dependency to its mfd driver gpiolib: add gpio_device_get_fwnode() helper mfd: ls2kbmc: Capture the reset event of BMC through GPIO mfd: ls2kbmc: Able to be compiled as a module drivers/char/ipmi/Kconfig | 2 +- drivers/gpio/gpiolib.c | 13 +++ drivers/mfd/Kconfig | 2 +- drivers/mfd/ls2k-bmc-core.c | 247 ++++++++++++++++++++++++++++++++++---------- include/linux/gpio/driver.h | 1 + 5 files changed, 206 insertions(+), 59 deletions(-) --- base-commit: 11028ab62899e4191e074ee364c712b77823a9c4 change-id: 20260626-ls2kbmc-mod-5209193009b2 Best regards, -- Miao Wang