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 2FE4F141981; Tue, 23 Jan 2024 01:07:29 +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=1705972049; cv=none; b=YxisAPcdiFzgCeg1u5dmuEZwe2GV20/qMx7jXVMUQe3BUY5/Azd7H3aSU3MstDOR2cgW6wryIcCtR+2lTRMceyGB08ZLZ2v8NIRlltQL/Ngxkdwdj0GcIiUAlCl/FcOe6UE+dfJKH6UyDeqN8WvyVpDmG0ekS+djut9ZopLzuao= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705972049; c=relaxed/simple; bh=P9q2fpyPeE9pxDxeu56mg75JVMwwYqEy+dZDrqzf5OM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=J/7Iq72wipFjb0zcBk/aY8r2xNhnenOymaN+x/NQspt5Q/eH7N/5xduGzrdNPExDf+Czld9xxufIovHyUiZ4j24ZkulabiJ4Qg7lZ1Z37m9c08OcPzBh19qH+iKnv0hGNAMqyMkgzdHVicJOdtxfW2PAPvNvXikQBgzpqa9F2g8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jOuDK5eM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="jOuDK5eM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DBD93C433C7; Tue, 23 Jan 2024 01:07:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705972049; bh=P9q2fpyPeE9pxDxeu56mg75JVMwwYqEy+dZDrqzf5OM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jOuDK5eMr0vWKxMC9+lV+IJjiTX7tnwHTgcIbOaqmzeeJfylUSSr07ORw3JGTf6aa cKeMaqsOPmMPJs9mBIW8qYQwlEu1SutZMHnsqxTxnGgrSYu4JccyWo5djy6tAcRJ7T YbcFC/F5w4IxpX4909QupOTOaJCVy+1mSIB2VFhU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marek Szyprowski , Chanho Park , Andi Shyti , Wolfram Sang , Sasha Levin Subject: [PATCH 6.1 414/417] i2c: s3c24xx: fix read transfers in polling mode Date: Mon, 22 Jan 2024 15:59:42 -0800 Message-ID: <20240122235806.024891136@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235751.480367507@linuxfoundation.org> References: <20240122235751.480367507@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marek Szyprowski [ Upstream commit 0d9cf23ed55d7ba3ab26d617a3ae507863674c8f ] To properly handle read transfers in polling mode, no waiting for the ACK state is needed as it will never come. Just wait a bit to ensure start state is on the bus and continue processing next bytes. Fixes: 117053f77a5a ("i2c: s3c2410: Add polling mode support") Signed-off-by: Marek Szyprowski Reviewed-by: Chanho Park Reviewed-by: Andi Shyti Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-s3c2410.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index 36dab9cd208c..2e43b6ccef2a 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -220,8 +220,17 @@ static bool is_ack(struct s3c24xx_i2c *i2c) int tries; for (tries = 50; tries; --tries) { - if (readl(i2c->regs + S3C2410_IICCON) - & S3C2410_IICCON_IRQPEND) { + unsigned long tmp = readl(i2c->regs + S3C2410_IICCON); + + if (!(tmp & S3C2410_IICCON_ACKEN)) { + /* + * Wait a bit for the bus to stabilize, + * delay estimated experimentally. + */ + usleep_range(100, 200); + return true; + } + if (tmp & S3C2410_IICCON_IRQPEND) { if (!(readl(i2c->regs + S3C2410_IICSTAT) & S3C2410_IICSTAT_LASTBIT)) return true; -- 2.43.0