From patchwork Thu Jan 13 18:44:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Konrad Dybcio X-Patchwork-Id: 531808 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03DE5C4332F for ; Thu, 13 Jan 2022 18:44:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237616AbiAMSok (ORCPT ); Thu, 13 Jan 2022 13:44:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237652AbiAMSoj (ORCPT ); Thu, 13 Jan 2022 13:44:39 -0500 Received: from relay03.th.seeweb.it (relay03.th.seeweb.it [IPv6:2001:4b7a:2000:18::164]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B0A8C06161C for ; Thu, 13 Jan 2022 10:44:38 -0800 (PST) Received: from localhost.localdomain (83.6.165.232.neoplus.adsl.tpnet.pl [83.6.165.232]) by m-r1.th.seeweb.it (Postfix) with ESMTPA id 103461F5EB; Thu, 13 Jan 2022 19:44:34 +0100 (CET) From: Konrad Dybcio To: ~postmarketos/upstreaming@lists.sr.ht Cc: martin.botka@somainline.org, angelogioacchino.delregno@somainline.org, marijn.suijten@somainline.org, jamipkettunen@somainline.org, Konrad Dybcio , Manivannan Sadhasivam , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] mtd: nand: raw: qcom_nandc: Don't clear_bam_transaction on READID Date: Thu, 13 Jan 2022 19:44:26 +0100 Message-Id: <20220113184427.2259509-1-konrad.dybcio@somainline.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org While I have absolutely 0 idea why and how, running clear_bam_transaction when READID is issued makes the DMA totally clog up and refuse to function at all on mdm9607. In fact, it is so bad that all the data gets garbled and after a short while in the nand probe flow, the CPU decides that sepuku is the only option. Removing _READID from the if condition makes it work like a charm, I can read data and mount partitions without a problem. Signed-off-by: Konrad Dybcio --- This is totally just an observation which took me an inhumane amount of debug prints to find.. perhaps there's a better reason behind this, but I can't seem to find any answers.. Therefore, this is a BIG RFC! drivers/mtd/nand/raw/qcom_nandc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c index 04e6f7b26706..506006ccdf1a 100644 --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -1459,8 +1459,7 @@ static void pre_command(struct qcom_nand_host *host, int command) clear_read_regs(nandc); - if (command == NAND_CMD_RESET || command == NAND_CMD_READID || - command == NAND_CMD_PARAM || command == NAND_CMD_ERASE1) + if (command == NAND_CMD_RESET || command == NAND_CMD_PARAM || command == NAND_CMD_ERASE1) clear_bam_transaction(nandc); }