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tty: amba-pl011: uart_amba_port is not available with earlycon function

PATCH New Shawn Guo 4 participants 4 messages Sep 17, 2016 – Sep 20, 2016

Subsystems (2)
TTY layer and serial drivers Arm primecell UART PL010 and PL011 drivers
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Shawn Guo

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#0 lore raw

PATCH 1/1 tty: amba-pl011: uart_amba_port is not available with earlycon function

Commit 0e125a5facf8 ("tty: amba-pl011: define flag register bits for ZTE device") changes earlycon function pl011_putc() to use a pointer to uart_amba_port. This causes a regression when earlycon is enabled, because uart_amba_port is not available yet at earlycon time. Let's revert the change on pl011_putc() to fix the regression.

The earlycon support for ZTE device can probably be added later by declaring a new earlycon setup function with a vendor specific compatible.

Reported-by Sudeep Holla <[email protected]>
Fixes 0e125a5facf8 ("tty: amba-pl011: define flag register bits for ZTE device")
Signed-off-by Shawn Guo <[email protected]>
---
 drivers/tty/serial/amba-pl011.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)
drivers/tty/serial/amba-pl011.c +1 -4
index 0b78b04e895e..2d9ffab16ffe 100644
@@ -2330,16 +2330,13 @@ static struct console amba_console = {
 
 static void pl011_putc(struct uart_port *port, int c)
 {
-	struct uart_amba_port *uap =
-		container_of(port, struct uart_amba_port, port);
-
 	while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
 		cpu_relax();
 	if (port->iotype == UPIO_MEM32)
 		writel(c, port->membase + UART01x_DR);
 	else
 		writeb(c, port->membase + UART01x_DR);
-	while (readl(port->membase + UART01x_FR) & uap->vendor->fr_busy)
+	while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
 		cpu_relax();
 }
Signature · 1 line
1.9.1
#1 lore raw

PATCH 1/1 tty: amba-pl011: uart_amba_port is not available with earlycon function

Quoted 6 lines · Shawn Guo

Commit 0e125a5facf8 ("tty: amba-pl011: define flag register bits for ZTE device") changes earlycon function pl011_putc() to use a pointer to uart_amba_port. This causes a regression when earlycon is enabled, because uart_amba_port is not available yet at earlycon time. Let's revert the change on pl011_putc() to fix the regression.

Quoted 7 lines

The earlycon support for ZTE device can probably be added later by declaring a new earlycon setup function with a vendor specific compatible.

Reported-by Sudeep Holla <[email protected]>
Fixes 0e125a5facf8 ("tty: amba-pl011: define flag register bits for ZTE device")
Signed-off-by Shawn Guo <[email protected]>

Hi Sudeep,

Can you please confirm if the patch fixes your problem, so that Greg knows whether it should be applied? Thanks.

Shawn

#2 lore raw

PATCH 1/1 tty: amba-pl011: uart_amba_port is not available with earlycon function

Quoted 11 lines · Shawn Guo
Quoted 10 lines · Shawn Guo

Commit 0e125a5facf8 ("tty: amba-pl011: define flag register bits for ZTE device") changes earlycon function pl011_putc() to use a pointer to uart_amba_port. This causes a regression when earlycon is enabled, because uart_amba_port is not available yet at earlycon time. Let's revert the change on pl011_putc() to fix the regression.

The earlycon support for ZTE device can probably be added later by declaring a new earlycon setup function with a vendor specific compatible.

Quoted 9 lines
Quoted 3 lines
Reported-by Sudeep Holla <[email protected]>
Fixes 0e125a5facf8 ("tty: amba-pl011: define flag register bits for ZTE device")
Signed-off-by Shawn Guo <[email protected]>

Hi Sudeep,

Can you please confirm if the patch fixes your problem, so that Greg knows whether it should be applied? Thanks.

Sorry, since it's basically what I tried first before posting some patch using private_data, I assumed it will work.

Anyways I have now tested it, so you can add:

Tested-by Sudeep Holla <[email protected]>
Signature · 2 lines
Regards,
Sudeep
#3 lore raw

PATCH 1/1 tty: amba-pl011: uart_amba_port is not available with earlycon function

Quoted 2 lines · Sudeep Holla

Anyways I have now tested it, so you can add:

Tested-by Sudeep Holla <[email protected]>

Sorry for the regression, and thanks much for the effort of issue reporting and testing.

Shawn