Linux-Serial Archive on lore.kernel.org
 help / color / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jonathan Bakker <xc-racer2@live.ca>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sasha Levin <sashal@kernel.org>,
	linux-serial@vger.kernel.org
Subject: [PATCH AUTOSEL 4.9 73/90] tty: serial: samsung: Correct clock selection logic
Date: Thu, 17 Sep 2020 22:14:38 -0400
Message-ID: <20200918021455.2067301-73-sashal@kernel.org> (raw)
In-Reply-To: <20200918021455.2067301-1-sashal@kernel.org>

From: Jonathan Bakker <xc-racer2@live.ca>

[ Upstream commit 7d31676a8d91dd18e08853efd1cb26961a38c6a6 ]

Some variants of the samsung tty driver can pick which clock
to use for their baud rate generation.  In the DT conversion,
a default clock was selected to be used if a specific one wasn't
assigned and then a comparison of which clock rate worked better
was done.  Unfortunately, the comparison was implemented in such
a way that only the default clock was ever actually compared.
Fix this by iterating through all possible clocks, except when a
specific clock has already been picked via clk_sel (which is
only possible via board files).

Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/BN6PR04MB06604E63833EA41837EBF77BA3A30@BN6PR04MB0660.namprd04.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/samsung.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index 4dfdb59061bea..8c89697c53573 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -1157,14 +1157,14 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 	struct s3c24xx_uart_info *info = ourport->info;
 	struct clk *clk;
 	unsigned long rate;
-	unsigned int cnt, baud, quot, clk_sel, best_quot = 0;
+	unsigned int cnt, baud, quot, best_quot = 0;
 	char clkname[MAX_CLK_NAME_LENGTH];
 	int calc_deviation, deviation = (1 << 30) - 1;
 
-	clk_sel = (ourport->cfg->clk_sel) ? ourport->cfg->clk_sel :
-			ourport->info->def_clk_sel;
 	for (cnt = 0; cnt < info->num_clks; cnt++) {
-		if (!(clk_sel & (1 << cnt)))
+		/* Keep selected clock if provided */
+		if (ourport->cfg->clk_sel &&
+			!(ourport->cfg->clk_sel & (1 << cnt)))
 			continue;
 
 		sprintf(clkname, "clk_uart_baud%d", cnt);
-- 
2.25.1


      parent reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200918021455.2067301-1-sashal@kernel.org>
2020-09-18  2:14 ` [PATCH AUTOSEL 4.9 53/90] serial: 8250_port: Don't service RX FIFO if throttled Sasha Levin
2020-09-18  2:14 ` [PATCH AUTOSEL 4.9 54/90] serial: 8250_omap: Fix sleeping function called from invalid context during probe Sasha Levin
2020-09-18  2:14 ` [PATCH AUTOSEL 4.9 55/90] serial: 8250: 8250_omap: Terminate DMA before pushing data on RX timeout Sasha Levin
2020-09-18  2:14 ` [PATCH AUTOSEL 4.9 64/90] serial: uartps: Wait for tx_empty in console setup Sasha Levin
2020-09-28 20:11   ` Naresh Kamboju
2020-09-28 20:13     ` Naresh Kamboju
2020-09-29  6:59       ` Greg Kroah-Hartman
2020-09-29 17:39         ` Sasha Levin
2020-09-18  2:14 ` Sasha Levin [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200918021455.2067301-73-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=krzk@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=xc-racer2@live.ca \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Serial Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-serial/0 linux-serial/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-serial linux-serial/ https://lore.kernel.org/linux-serial \
		linux-serial@vger.kernel.org
	public-inbox-index linux-serial

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-serial


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git