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authorAhung Cheng <ahcheng@nvidia.com>2019-08-12 16:58:13 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-04 12:43:54 +0200
commit18a4c404d2b4de47da519955ddda0b153c03f12d (patch)
tree9646656d1b4027f00878473791ecce9e1b2badec /drivers/tty
parent6300b140c29fdcd45e84fb551196a6e38dadddcc (diff)
serial: tegra: protect IER against LCR.DLAB
The IER and DLH registers occupy the same address space, selected by the LCR.DLAB bit. Hence, add port lock to protect IER when LCR.DLAB bit is set. Signed-off-by: Ahung Cheng <ahcheng@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/1565609303-27000-5-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/serial-tegra.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index 83cc8dca58d4..82a8d5130cbc 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -294,6 +294,7 @@ static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
unsigned long rate;
unsigned int divisor;
unsigned long lcr;
+ unsigned long flags;
int ret;
if (tup->current_baud == baud)
@@ -313,6 +314,7 @@ static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
divisor = DIV_ROUND_CLOSEST(rate, baud * 16);
}
+ spin_lock_irqsave(&tup->uport.lock, flags);
lcr = tup->lcr_shadow;
lcr |= UART_LCR_DLAB;
tegra_uart_write(tup, lcr, UART_LCR);
@@ -325,6 +327,7 @@ static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
/* Dummy read to ensure the write is posted */
tegra_uart_read(tup, UART_SCR);
+ spin_unlock_irqrestore(&tup->uport.lock, flags);
tup->current_baud = baud;