From patchwork Mon Jan 8 06:20:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shinichiro Kawasaki X-Patchwork-Id: 760947 Received: from esa5.hgst.iphmx.com (esa5.hgst.iphmx.com [216.71.153.144]) (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 57701BE6B; Mon, 8 Jan 2024 06:22:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wdc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="WY76uHE4" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1704694932; x=1736230932; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=MScuqBO0++OAVopMRx9sYKbuxXydYzh/BbhazA8/gwM=; b=WY76uHE44TA6QuPFXpMe9DMc95JXa12x4xXNsQ979yCRwFLERPv6tfcr Qa1QG/ev6xUsr1cAAJL2olqRqsaNTmETWvH+yRP6YzFo98aD2Sqb+cmT1 T6oh0/i7T452UnaeO+PKV012Ap9smwm4vWP5IbsyXXohSBwS3wV3ZrixP +HsNuu0Z1Lsoxz5l0W6plVram+qeyVVFokKtxbLbR+D642ocuSoV6hBVE lbuagaAtRTnF5ACQkkhKedbCnRy8yPjGkVyFbalZu5wG23kii+Kcjw/jA jvu8/9BZPH217cFJumedsqGEyKtLI4J3gzO9zbQBL2dFUCxX97JBFYn7f A==; X-CSE-ConnectionGUID: WzbhtLZgSZyMK9I1x3VoFA== X-CSE-MsgGUID: nDxwfq8ETuKm2UApnhy2PQ== X-IronPort-AV: E=Sophos;i="6.04,340,1695657600"; d="scan'208";a="6822647" Received: from h199-255-45-14.hgst.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 08 Jan 2024 14:21:03 +0800 IronPort-SDR: OnMz/hNj7LtqATKip3TM4UCBoNeVordoHwfce89WNhfcqmZIbrME7/qK6HGhZ9Vzzfx4xhUuMn Wv1eVTZZ+Rfw== Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 07 Jan 2024 21:31:24 -0800 IronPort-SDR: NU7YKTDAS31nyY09lUsZhxHDCfLB9MIgQr09nAAT39vyVBa7+yHJmlvxao4nWB55TvOGOfWnBg Oy1ufhTf+ZUg== WDCIronportException: Internal Received: from unknown (HELO shindev.ssa.fujisawa.hgst.com) ([10.149.66.30]) by uls-op-cesaip02.wdc.com with ESMTP; 07 Jan 2024 22:21:01 -0800 From: Shin'ichiro Kawasaki To: platform-driver-x86@vger.kernel.org Cc: Hans de Goede , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Andy Shevchenko , Lukas Wunner , Klara Modin , linux-pci@vger.kernel.org, linux-i2c@vger.kernel.org, Shin'ichiro Kawasaki Subject: [PATCH v6 0/2] platform/x86: p2sb: Fix deadlock at sysfs PCI bus rescan Date: Mon, 8 Jan 2024 15:20:57 +0900 Message-ID: <20240108062059.3583028-1-shinichiro.kawasaki@wdc.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 When PCI devices call p2sb_bar() during probe for sysfs PCI bus rescan, deadlock happens due to double lock of pci_rescan_remove_lock [1]. The first patch in this series addresses the deadlock. The second patch is a code improvement which was pointed out during review for the first patch. [1] https://lore.kernel.org/linux-pci/6xb24fjmptxxn5js2fjrrddjae6twex5bjaftwqsuawuqqqydx@7cl3uik5ef6j/ The first patch of the v5 series was upstreamed to the kernel v6.7-rc8. However, it caused IDE controller detection failure on an old platform [2] then the patch was reverted at v6.7. The failure happened because the IDE controller had same DEVFN as P2SB device. To avoid this failure, I added device class check per suggestion by Lukas. If the device at P2SB DEVFN does not have the device class expected for P2SB, avoid touching the device. [2] https://lore.kernel.org/platform-driver-x86/CABq1_vjfyp_B-f4LAL6pg394bP6nDFyvg110TOLHHb0x4aCPeg@mail.gmail.com/ I confirmed the patches fix the problem [1] on the kernel v6.7, using a system with i2c_i801 device, building i2c_i801 module as both built-in and loadable. Reviews and comments will be appreciated. Klara, I hesitated to add your Tested-by tag to the v6 patch, since I modified the code slightly from the code you tested (I used pci_bus_read_config_word() instead of pci_bus_read_config_dword() to avoid a shift operator). I hope you have time to afford to test this series again. Changes from v5: * Added device class check to avoid old IDE controller detection failure Changes from v4: * Separated a hunk for pci_resource_n() as the second patch * Reflected other review comments by Ilpo Changes from v3: * Modified p2sb_valid_resource() to return boolean Changes from v2: * Improved p2sb_scan_and_cache() and p2sb_scan_and_cache_devfn() * Reflected other review comments by Andy Changes from v1: * Reflected review comments by Andy * Removed RFC prefix Changes from RFC v2: * Reflected review comments on the list Changes from RFC v1: * Fixed a build warning poitned out in llvm list by kernel test robot Shin'ichiro Kawasaki (2): platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe platform/x86: p2sb: Use pci_resource_n() in p2sb_read_bar0() drivers/platform/x86/p2sb.c | 183 +++++++++++++++++++++++++++--------- 1 file changed, 141 insertions(+), 42 deletions(-)