This is a note to let you know that I've just added the patch titled
serial: amba-pl011: do not request memory region twice
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-amba-pl011-do-not-request-memory-region-twice.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ffc3639650c1dca24fb8db35d161219361b0c388
Author: Lino Sanfilippo <LinoSanfilippo@xxxxxx>
Date: Mon Nov 29 18:42:38 2021 +0100
serial: amba-pl011: do not request memory region twice
[ Upstream commit d1180405c7b5c7a1c6bde79d5fc24fe931430737 ]
With commit 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()") the
function devm_ioremap() called from pl011_setup_port() was replaced with
devm_ioremap_resource(). Since this function not only remaps but also
requests the ports io memory region it now collides with the .config_port()
callback which requests the same region at uart port registration.
Since devm_ioremap_resource() already claims the memory successfully, the
request in .config_port() fails.
Later at uart port deregistration the attempt to release the unclaimed
memory also fails. The failure results in a “Trying to free nonexistent
resource" warning.
Fix these issues by removing the callbacks that implement the redundant
memory allocation/release. Also make sure that changing the drivers io
memory base address via TIOCSSERIAL is not allowed any more.
Fixes: 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()")
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@xxxxxx>
Link: https://lore.kernel.org/r/20211129174238.8333-1-LinoSanfilippo@xxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 6741d0f3daf94..0bd8c05d72d60 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2094,32 +2094,13 @@ static const char *pl011_type(struct uart_port *port)
return uap->port.type == PORT_AMBA ? uap->type : NULL;
}
-/*
- * Release the memory region(s) being used by 'port'
- */
-static void pl011_release_port(struct uart_port *port)
-{
- release_mem_region(port->mapbase, SZ_4K);
-}
-
-/*
- * Request the memory region(s) being used by 'port'
- */
-static int pl011_request_port(struct uart_port *port)
-{
- return request_mem_region(port->mapbase, SZ_4K, "uart-pl011")
- != NULL ? 0 : -EBUSY;
-}
-
/*
* Configure/autoconfigure the port.
*/
static void pl011_config_port(struct uart_port *port, int flags)
{
- if (flags & UART_CONFIG_TYPE) {
+ if (flags & UART_CONFIG_TYPE)
port->type = PORT_AMBA;
- pl011_request_port(port);
- }
}
/*
@@ -2134,6 +2115,8 @@ static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
ret = -EINVAL;
if (ser->baud_base < 9600)
ret = -EINVAL;
+ if (port->mapbase != (unsigned long) ser->iomem_base)
+ ret = -EINVAL;
return ret;
}
@@ -2151,8 +2134,6 @@ static const struct uart_ops amba_pl011_pops = {
.flush_buffer = pl011_dma_flush_buffer,
.set_termios = pl011_set_termios,
.type = pl011_type,
- .release_port = pl011_release_port,
- .request_port = pl011_request_port,
.config_port = pl011_config_port,
.verify_port = pl011_verify_port,
#ifdef CONFIG_CONSOLE_POLL
@@ -2182,8 +2163,6 @@ static const struct uart_ops sbsa_uart_pops = {
.shutdown = sbsa_uart_shutdown,
.set_termios = sbsa_uart_set_termios,
.type = pl011_type,
- .release_port = pl011_release_port,
- .request_port = pl011_request_port,
.config_port = pl011_config_port,
.verify_port = pl011_verify_port,
#ifdef CONFIG_CONSOLE_POLL
