[Xen-devel] [PATCH 3 of 5] xen: Restore the BAR and PCI command after resume

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

# HG changeset patch
# User Roger Cruz <roger.cruz@xxxxxxxxxxxxxxxxxxx>
# Date 1310490365 14400
# Node ID ded47a2ba411fefc614c773ae78518a162f912f9
# Parent  4c94bcf4b4afb840bc6a037f0782c63ad573f4eb
xen: Restore the BAR and PCI command after resume.

Certain PCI serial cards just don't want to remember
what they are when they come out of resume. Save
the BAR and the PCI command values before we suspend and
write them back in when we resume.

Signed-off-by: Roger Cruz <roger.cruz@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Tom Goetz <tom.goetz@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

diff -r 4c94bcf4b4af -r ded47a2ba411 xen/drivers/char/ns16550.c
--- a/xen/drivers/char/ns16550.c        Tue Jul 12 13:06:05 2011 -0400
+++ b/xen/drivers/char/ns16550.c        Tue Jul 12 13:06:05 2011 -0400
@@ -49,6 +49,7 @@ static struct ns16550 {
     unsigned int ps_bdf[3]; /* pci serial port BDF */
     bool_t pb_bdf_enable;   /* if =1, pb-bdf effective, port behind bridge */
     bool_t ps_bdf_enable;   /* if =1, ps_bdf effective, port on pci card */
+    int bar0, cr;
 } ns16550_com[2] = { { 0 } };
 
 /* Register offsets */
@@ -332,8 +333,17 @@ static void __init ns16550_init_postirq(
 
 static void ns16550_resume(struct serial_port *port)
 {
+    struct ns16550 *uart = port->uart;
+
     ns16550_setup_preirq(port->uart);
     ns16550_setup_postirq(port->uart);
+
+    if (uart->bar0) {
+       pci_conf_write32(uart->pb_bdf[0], uart->pb_bdf[1], uart->pb_bdf[2],
+                        PCI_BASE_ADDRESS_0, uart->bar0);
+       pci_conf_write32(uart->pb_bdf[0], uart->pb_bdf[1], uart->pb_bdf[2],
+                        PCI_COMMAND, uart->cr);
+    }
 }
 
 #ifdef CONFIG_X86
@@ -358,6 +368,12 @@ static void ns16550_suspend(struct seria
     struct ns16550 *uart = port->uart;
 
     stop_timer(&uart->timer);
+    if (uart->bar0) {
+       uart->bar0 = pci_conf_read32(uart->pb_bdf[0], uart->pb_bdf[1], 
uart->pb_bdf[2],
+                                    PCI_BASE_ADDRESS_0);
+       uart->cr = pci_conf_read32(uart->pb_bdf[0], uart->pb_bdf[1], 
uart->pb_bdf[2],
+                                    PCI_COMMAND);
+    }
 }
 
 static struct uart_driver __read_mostly ns16550_driver = {
@@ -480,6 +496,10 @@ magic_uart_config (struct ns16550 *uart,
               if ((len & 0xffff) != 0xfff9)
                 continue;
 
+              uart->pb_bdf[0] = b;
+              uart->pb_bdf[1] = d;
+              uart->pb_bdf[2] = f;
+              uart->bar0 = bar0;
               uart->io_base = bar0 & 0xfffe;
               uart->irq = 0;
 



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