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| author | Jonathan Bakker <xc-racer2@live.ca> | 2020-05-08 18:34:33 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-01 13:12:43 +0200 |
| commit | 3d01f225c61c2127ba4f79713cb696e71620f21d (patch) | |
| tree | a22cc4fa303b2c0b178a9ff6e6f54c88aedad0ed /drivers/tty | |
| parent | 34307affd96900fbdc9b601e2a13ae02a25efbca (diff) | |
| download | linux-stable-3d01f225c61c2127ba4f79713cb696e71620f21d.tar.gz linux-stable-3d01f225c61c2127ba4f79713cb696e71620f21d.tar.bz2 linux-stable-3d01f225c61c2127ba4f79713cb696e71620f21d.zip | |
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>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/samsung.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index c67d39fea74c..70d29b697e82 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -1165,14 +1165,14 @@ 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); |