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authorJonathan Bakker <xc-racer2@live.ca>2020-05-08 18:34:33 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-10-01 11:11:55 +0200
commitf5dcf3fd4416705946d1fc18c9b6d9ae18af3fd1 (patch)
treefdd423f28128b327514e9a035fdcf4f01963c609
parent3244190d24cc0269497483fd8fb6b73b9d09b0d3 (diff)
tty: serial: samsung: Correct clock selection logic
[ 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>
-rw-r--r--drivers/tty/serial/samsung.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index 70a51d0bc604..42aa37515e9b 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -1151,14 +1151,14 @@ 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);