Revert "serial: 8250_mtk: Make sure to select the right FEATURE_SEL"

It was found that some MediaTek SoCs are incompatible with this
change. Also, this register was mistakenly understood as it was
related to the 16550A register layout selection but, at least
on some IPs, if not all, it's related to something else unknown.

This reverts commit 6f81fdded0d024c7d4084d434764f30bca1cd6b1.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Fixes: 6f81fdded0d0 ("serial: 8250_mtk: Make sure to select the right FEATURE_SEL")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Link: https://lore.kernel.org/r/20220510122620.150342-1-angelogioacchino.delregno@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 21053db93ff1e5ad546a21e79b9485dee2213b89..54051ec7b49927e57b730e48fb0123257ab9f716 100644 (file)
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -54,9 +54,6 @@
 #define MTK_UART_TX_TRIGGER    1
 #define MTK_UART_RX_TRIGGER    MTK_UART_RX_SIZE
 
-#define MTK_UART_FEATURE_SEL   39      /* Feature Selection register */
-#define MTK_UART_FEAT_NEWRMAP  BIT(0)  /* Use new register map */
-
 #define MTK_UART_XON1          40      /* I/O: Xon character 1 */
 #define MTK_UART_XOFF1         42      /* I/O: Xoff character 1 */
 
@@ -575,10 +572,6 @@ static int mtk8250_probe(struct platform_device *pdev)
                uart.dma = data->dma;
 #endif
 
-       /* Set AP UART new register map */
-       writel(MTK_UART_FEAT_NEWRMAP, uart.port.membase +
-              (MTK_UART_FEATURE_SEL << uart.port.regshift));
-
        /* Disable Rate Fix function */
        writel(0x0, uart.port.membase +
                        (MTK_UART_RATE_FIX << uart.port.regshift));