From 7d31676a8d91dd18e08853efd1cb26961a38c6a6 Mon Sep 17 00:00:00 2001 From: Jonathan Bakker Date: Fri, 8 May 2020 18:34:33 -0700 Subject: [PATCH] tty: serial: samsung: Correct clock selection logic 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 Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/BN6PR04MB06604E63833EA41837EBF77BA3A30@BN6PR04MB0660.namprd04.prod.outlook.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/samsung_tty.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 6ef614d8648c..d913d9b2762a 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -1304,14 +1304,14 @@ 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);