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 [thread overview]
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
prev parent reply other threads:[~2020-09-18 2:16 UTC|newest]
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]
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