From patchwork Fri Apr 15 16:54:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiner Kallweit X-Patchwork-Id: 562033 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 E6EF2C433EF for ; Fri, 15 Apr 2022 17:00:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356033AbiDORCc (ORCPT ); Fri, 15 Apr 2022 13:02:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356054AbiDORC3 (ORCPT ); Fri, 15 Apr 2022 13:02:29 -0400 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C648B3E5C9 for ; Fri, 15 Apr 2022 09:59:59 -0700 (PDT) Received: by mail-ed1-x534.google.com with SMTP id b15so10519294edn.4 for ; Fri, 15 Apr 2022 09:59:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language :from:to:cc:references:in-reply-to:content-transfer-encoding; bh=J0MymH7xtuu9E48UR9lg1o6xdrHIesht/4b5Wb50scs=; b=ChFHSrLLHfk+v+xhFOgz0Ou9lj2yJJPnZvBJTZS4hXK6BnWm8urfGusOKe8X6uP6vv OYBjb4TOpWkwDKCQpNti3z2aI3VY3xwapCtEI66T+5vF9orNkREca0xzmEddL1yAK62L P7WzJETBQePvFtc1iBmDWxMVgCt4auHjeHhu4/swWCNhgNQPobNK5+TgSXg/IXSPaoUt Fl9Zrtkl85GXyJV1dUSBOnDqvAEkYYeEEoaHARWY7hQLk7154xN2utnQsBfwHpQBHrN5 XI3+ezGDagGKDpW/dpZzSj+xnOvzki6b7OsWGL/Wi2cg41NVNjT4PiPOsuju6xZAa30J ak5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:from:to:cc:references:in-reply-to :content-transfer-encoding; bh=J0MymH7xtuu9E48UR9lg1o6xdrHIesht/4b5Wb50scs=; b=rU4DlNVd6s0cyQJBhnizU3rlDuVa9NJvu5k85YJ5qM+ToQWkS9+4jLYIxlexI9R4Mm PHNL5y7wF17ep/OlnpMzhakkucjoxyZkWm8s6SENvUq1ic2linwOmk5bNeNxhUwNohr4 AtayzlBzwp1iZyulQwqWGURDvuuAgbDLzm/9S7j2YQpgvV8wzrD5HWQbgmjcMgJWMIPK SDq9n16cHU2G7grBBvNVIc4AHY9EDzSTygwzPl4ZdrlR92iAorpUkKmeO2tLWgHru0EV SFa5puCDKKuGYWIHYER8OmdnbJ4q3chpDjWafUk3P2vsFnmS9+z9DpLzZPib+iK1V8NL bPPg== X-Gm-Message-State: AOAM531kFT3Zlcmaosyzcy6YzcCDahuGL72Bhn5SOQcbR96EDNbZcXNz FMcpeSMjbjGKMspx4Ghlam8DmT8c9Qk= X-Google-Smtp-Source: ABdhPJwa0P0d7u/ram1ThJ5YXF2F281QeMBTG3sctlUeBBES5l36Oj7uZ5aN0kNhIVi1Uh7HIg6xDA== X-Received: by 2002:aa7:c793:0:b0:408:4a69:90b4 with SMTP id n19-20020aa7c793000000b004084a6990b4mr194081eds.58.1650041998274; Fri, 15 Apr 2022 09:59:58 -0700 (PDT) Received: from ?IPV6:2a01:c22:6faa:ed00:b906:e23f:946b:b9f7? (dynamic-2a01-0c22-6faa-ed00-b906-e23f-946b-b9f7.c22.pool.telefonica.de. [2a01:c22:6faa:ed00:b906:e23f:946b:b9f7]) by smtp.googlemail.com with ESMTPSA id 10-20020a170906310a00b006e834953b55sm1803245ejx.27.2022.04.15.09.59.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 15 Apr 2022 09:59:57 -0700 (PDT) Message-ID: <05bec021-6958-0157-b825-619ac21ddd41@gmail.com> Date: Fri, 15 Apr 2022 18:54:32 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: [PATCH 1/8] i2c: i801: improve interrupt handler Content-Language: en-US From: Heiner Kallweit To: Jean Delvare Cc: "linux-i2c@vger.kernel.org" References: <4125f9ce-ce5f-fbcf-7d6f-9bc586ac43e0@gmail.com> In-Reply-To: <4125f9ce-ce5f-fbcf-7d6f-9bc586ac43e0@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Not sure if it can happen, but better play safe: If SMBHSTSTS_BYTE_DONE and an error flag is set, then don't trust the result and skip calling i801_isr_byte_done(). In addition clear status bit SMBHSTSTS_BYTE_DONE in the main interrupt handler, this allows to simplify the code a little. Signed-off-by: Heiner Kallweit --- drivers/i2c/busses/i2c-i801.c | 25 ++++++++----------------- 1 file changed, 8 insertions(+), 17 deletions(-) diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index ff706349b..c481f121d 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -556,9 +556,6 @@ static void i801_isr_byte_done(struct i801_priv *priv) /* Write next byte, except for IRQ after last byte */ outb_p(priv->data[++priv->count], SMBBLKDAT(priv)); } - - /* Clear BYTE_DONE to continue with next byte */ - outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv)); } static irqreturn_t i801_host_notify_isr(struct i801_priv *priv) @@ -588,7 +585,6 @@ static irqreturn_t i801_host_notify_isr(struct i801_priv *priv) * BUS_ERR - SMI# transaction collision * FAILED - transaction was canceled due to a KILL request * When any of these occur, update ->status and signal completion. - * ->status must be cleared before kicking off the next transaction. * * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt * occurs for each byte of a byte-by-byte to prepare the next byte. @@ -613,23 +609,18 @@ static irqreturn_t i801_isr(int irq, void *dev_id) } status = inb_p(SMBHSTSTS(priv)); - if (status & SMBHSTSTS_BYTE_DONE) + if ((status & SMBHSTSTS_BYTE_DONE) && !(status & STATUS_ERROR_FLAGS)) i801_isr_byte_done(priv); /* - * Clear remaining IRQ sources: Completion of last command, errors - * and the SMB_ALERT signal. SMB_ALERT status is set after signal - * assertion independently of the interrupt generation being blocked - * or not so clear it always when the status is set. - */ - status &= SMBHSTSTS_INTR | STATUS_ERROR_FLAGS | SMBHSTSTS_SMBALERT_STS; - if (status) - outb_p(status, SMBHSTSTS(priv)); - status &= ~SMBHSTSTS_SMBALERT_STS; /* SMB_ALERT not reported */ - /* - * Report transaction result. - * ->status must be cleared before the next transaction is started. + * Clear IRQ sources: SMB_ALERT status is set after signal assertion + * independently of the interrupt generation being blocked or not + * so clear it always when the status is set. */ + status &= STATUS_FLAGS | SMBHSTSTS_SMBALERT_STS; + outb_p(status, SMBHSTSTS(priv)); + + status &= STATUS_ERROR_FLAGS | SMBHSTSTS_INTR; if (status) { priv->status = status; complete(&priv->done);