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 3173312FF86; Tue, 23 Jan 2024 00:17:45 +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=1705969065; cv=none; b=u+/lqJdBZ8YJzmHz4Rd3BjlksqoIlxpNqlWG1dqq7V0NqWS8bkgAZMle4NmpcIiXpyuC/zsCboFyEIdYQZ5NatteF/WL9wJiRDlRCBOVV95VEYnATiUjGLGhLQ6F1tDuwQ9pGTIj1wr+rev8EEUTVOTJ/AyUtoOQjddT5B1ch8s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705969065; c=relaxed/simple; bh=v8HeZwawHKWq/k9juLI37GVy55OaDkYWZ3n5IUxIKHs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JGm8+mLa6qUAiMAC8LIIlEtF2mpHDHNKk9xaTW57bg8tSt7C7H0ym7VnWs8B57mtBYra2yxpKfWBrPiOMKimRoZE+MstCrZNtSjV8TOIfGF4r9lOeJKqb5NwibycqRyWUnkHDusJd1ViqIZo+RPoTP3iJ5FCPYg0K7Vsob/Wh8o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LdhYt+IR; 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="LdhYt+IR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2622C433C7; Tue, 23 Jan 2024 00:17:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705969065; bh=v8HeZwawHKWq/k9juLI37GVy55OaDkYWZ3n5IUxIKHs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LdhYt+IR05GJ/ooMWYhT5J+JKbZ3SjLzPVGLOM0TRM9NiEizPDHtY2soBM77ozNq3 2a/X09tS3tR4nxNrKp1nSqfkb+tBad4NyvHU2USaCtwYJsYv6LA3stumSDnNuVNPUC v/pTlnJiOtYAk7dvaxodU19EIWCPQ2bFQdqIAXKs= 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 5.4 192/194] i2c: s3c24xx: fix read transfers in polling mode Date: Mon, 22 Jan 2024 15:58:42 -0800 Message-ID: <20240122235727.449401875@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235719.206965081@linuxfoundation.org> References: <20240122235719.206965081@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-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 e6f927c6f8af..a306f8e6702b 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -223,8 +223,17 @@ 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