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 7C0BD65BD3; Tue, 23 Jan 2024 01:58:22 +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=1705975102; cv=none; b=MQekc27cR314SnztuH69Bd+BLoJTyD/dLZ0ywe7rj7TdzW2EmIIa3AKLfmxf3z8Jm++veIDeEMvYlHCBkACQI+XYgYpQ4zEKGwNRH1TobGdkUZHzgn0Y/hzWQfGDN3geIh7A7+C0udipBHFIiZ4UwSEOGTM12sgqeTXqeVaIgAA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705975102; c=relaxed/simple; bh=EG8XbP3GIwhxk8LpXG99jpLF7PsDuM1zo3nKA4LbNMg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tJpWLayajZWJFHeTpL7aKSrB6EZn+HTkLUjP2UvxJtsxIsj4ZDmeK82svAi2jxTDWAVdNQO+vXtP8YxWYgQHvpdoWZWOwqldRlidWLnI7v+0ro3ivfh7nIuD1w/iJO72RL84DYlCF9d+uboec50euT3VSEVfqoHQaXmXUR/advg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IAFEgk3i; 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="IAFEgk3i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 446E0C433C7; Tue, 23 Jan 2024 01:58:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705975102; bh=EG8XbP3GIwhxk8LpXG99jpLF7PsDuM1zo3nKA4LbNMg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IAFEgk3iAvePfbeP8n3yQEpX6DwAAaaPP3X7zWpFPNUM6moRNIHcjHfc0h1pb6o+H gh8vLpKOAV7BX/NitWkxf60iPNt10tVD79iDsztuxzZTcUekMBtlOdKj8avKNpRqXJ TLL+oqjPqhT07L5uHl9Eahkr1JInz/atKFfXB+84= 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 5.15 366/374] i2c: s3c24xx: fix read transfers in polling mode Date: Mon, 22 Jan 2024 16:00:22 -0800 Message-ID: <20240122235757.694471644@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235744.598274724@linuxfoundation.org> References: <20240122235744.598274724@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 5.15-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 b49a1b170bb2..9a6fbb38a5ba 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