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 5E3D050A77; Tue, 23 Jan 2024 00:39:39 +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=1705970379; cv=none; b=bqo1DLnAV0iNWOhCqoXHHzHE7sCA23pWawaEnZRsUxfutCUf73I3cLL3L6pAyskWQ5FC5pBN9utf5/xkDuGOFeaJjBNwo/stJx0jTrVsgpLiPf8yhSPTLt+iFVZDXN2x7PvCQ9Zx+wYcQccF9gtcKCTib/9ACq/NvjCmoOLrOf8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705970379; c=relaxed/simple; bh=RS/x/BOVIRZ8kzoRzmHvbAOJjtyAEzwHr1i0kQC3eCI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kal7cvzrTWrpw87iGA2RxHVwa5u/abIRwfey+tJYWT9PSQzqxLMbptPVk1kvNQsi7GGBDgTw4P2cAEYtQx55dQH88zIwfYxxRKm3Tn+fSyUuBLFPNF6g/an1XLWzc/SOqARpZgtFa9A/EqZD4hG6ebOqpAZjFbQ5tVKoSUVZWUk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Y8+Qy7H1; 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="Y8+Qy7H1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3DB8C433F1; Tue, 23 Jan 2024 00:39:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705970379; bh=RS/x/BOVIRZ8kzoRzmHvbAOJjtyAEzwHr1i0kQC3eCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y8+Qy7H1qdoAXWHunB+eioZ20zYtxYD9fqVBbebr7aGswCBfZpx35di2+YkRCdIQH W7hE5jXkvwEMmBWcNXXHtO5dya+UjLh7zOHj3C4dNiWEaz0HQvKBeMayszbda44gfN X7WZHAYewNXJ1MIftsEiTB1yjQQHmB5x5/wqBz7w= 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 6.7 640/641] i2c: s3c24xx: fix read transfers in polling mode Date: Mon, 22 Jan 2024 15:59:04 -0800 Message-ID: <20240122235838.306631307@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235818.091081209@linuxfoundation.org> References: <20240122235818.091081209@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 6.7-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 c56886af724e..bf9a5670ef33 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -216,8 +216,17 @@ 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