serial: amba-pl011: do not request memory region twice

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@gmx.de>
Link: https://lore.kernel.org/r/20211129174238.8333-1-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index c9534e2..e2927a6 100644 (file)
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2152,31 +2152,12 @@ static const char *pl011_type(struct uart_port *port)
 }
 
 /*
- * 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);
-       }
 }
 
 /*
@@ -2191,6 +2172,8 @@ 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;
 }
 
@@ -2243,8 +2226,6 @@ 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
@@ -2274,8 +2255,6 @@ 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