From patchwork Mon Nov 13 05:19:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Ellerman X-Patchwork-Id: 1863015 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=Fpx+Jibn; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=patchwork.ozlabs.org) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4STHmx58fvz1yRD for ; Mon, 13 Nov 2023 16:20:01 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=Fpx+Jibn; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4STHmw3cDqz3cCv for ; Mon, 13 Nov 2023 16:20:00 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=Fpx+Jibn; dkim-atps=neutral Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4STHmZ4wPgz3cCM for ; Mon, 13 Nov 2023 16:19:42 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1699852782; bh=BxI1lsBuCW4vDoLChi5IWUDcx7NqULHserKaaGQ0G1U=; h=From:To:Cc:Subject:Date:From; b=Fpx+JibnVfzjHPeWzooUCtfbofmUjPjGQ7N2weWLylXHI8QCMWXRg4bWpQ+Vq7f8V pXok3ZvVbnvh3/lChKFS1uPL1gZa+07Y2OAOXN1jnuHCQaPo53aQzQMNtDKqqW4WOf Nax/wNxUoo8MaJ7i1qeFn+lRXaYG1Zs4gIQxVav5pgoTqOOy7XZzv5gC4UDTwn5va3 GWWaI1R+HumR6j3B8SjOQZUa6g/JtzoIQReGyB+M/DxRJqa3jElcZWoCcEZPMkO/pk WSqi7aT7LmtzGLaNFLJffmOpF4AocDj90Lf/m6rG0Qkzio9v83w45YbL8vWarYMtaS XIAMBhIFDf2Ag== Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4STHmZ1Qvcz4x3D; Mon, 13 Nov 2023 16:19:42 +1100 (AEDT) From: Michael Ellerman To: Subject: [PATCH] powerpc/32: Drop unused grackle_set_stg() Date: Mon, 13 Nov 2023 16:19:29 +1100 Message-ID: <20231113051929.1952351-1-mpe@ellerman.id.au> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: bhelgaas@google.com, nathan@kernel.org, ndesaulniers@google.com Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The call to grackle_set_stg() ("Store Gathering") has always been inside an #ifdef 0, since the code was first merged in v2.3.43pre7. Apparently it was suspected of causing problems on some hardware so was disabled. No one has ever proved otherwise so drop the code as unused for now. Reported-by: kernel test robot Reported-by: Bjorn Helgaas Closes: https://lore.kernel.org/all/20231031145600.GA9161@bhelgaas/ Signed-off-by: Michael Ellerman --- arch/powerpc/sysdev/grackle.c | 19 ------------------- 1 file changed, 19 deletions(-) Some additional detail too verbose/boring for the change log. Initial commit introducing the code, under #ifdef 0: https://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux-fullhistory.git/tree/arch/ppc/kernel/pmac_pci.c?id=2fac5cbf1dd9a7720aa0130575a0b36ba4f04ede#n623 Discussion of the hardware problems it might have caused, but with no meaningful conclusion: https://lore.kernel.org/all/20000903134303.2744@192.168.1.10/ diff --git a/arch/powerpc/sysdev/grackle.c b/arch/powerpc/sysdev/grackle.c index fd2f94a884f0..7dce8278b71e 100644 --- a/arch/powerpc/sysdev/grackle.c +++ b/arch/powerpc/sysdev/grackle.c @@ -18,24 +18,8 @@ #define GRACKLE_CFA(b, d, o) (0x80 | ((b) << 8) | ((d) << 16) \ | (((o) & ~3) << 24)) -#define GRACKLE_PICR1_STG 0x00000040 #define GRACKLE_PICR1_LOOPSNOOP 0x00000010 -/* N.B. this is called before bridges is initialized, so we can't - use grackle_pcibios_{read,write}_config_dword. */ -static inline void grackle_set_stg(struct pci_controller* bp, int enable) -{ - unsigned int val; - - out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8)); - val = in_le32(bp->cfg_data); - val = enable? (val | GRACKLE_PICR1_STG) : - (val & ~GRACKLE_PICR1_STG); - out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8)); - out_le32(bp->cfg_data, val); - (void)in_le32(bp->cfg_data); -} - static inline void grackle_set_loop_snoop(struct pci_controller *bp, int enable) { unsigned int val; @@ -56,7 +40,4 @@ void __init setup_grackle(struct pci_controller *hose) pci_add_flags(PCI_REASSIGN_ALL_BUS); if (of_machine_is_compatible("AAPL,PowerBook1998")) grackle_set_loop_snoop(hose, 1); -#if 0 /* Disabled for now, HW problems ??? */ - grackle_set_stg(hose, 1); -#endif }