summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--drivers/pcmcia/topic.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/pcmcia/topic.h b/drivers/pcmcia/topic.h
index 615a45a8fe86..582688fe7505 100644
--- a/drivers/pcmcia/topic.h
+++ b/drivers/pcmcia/topic.h
@@ -104,6 +104,9 @@
#define TOPIC_EXCA_IF_CONTROL 0x3e /* 8 bit */
#define TOPIC_EXCA_IFC_33V_ENA 0x01
+#define TOPIC_PCI_CFG_PPBCN 0x3e /* 16-bit */
+#define TOPIC_PCI_CFG_PPBCN_WBEN 0x0400
+
static void topic97_zoom_video(struct pcmcia_socket *sock, int onoff)
{
struct yenta_socket *socket = container_of(sock, struct yenta_socket, socket);
@@ -138,6 +141,7 @@ static int topic97_override(struct yenta_socket *socket)
static int topic95_override(struct yenta_socket *socket)
{
u8 fctrl;
+ u16 ppbcn;
/* enable 3.3V support for 16bit cards */
fctrl = exca_readb(socket, TOPIC_EXCA_IF_CONTROL);
@@ -146,6 +150,18 @@ static int topic95_override(struct yenta_socket *socket)
/* tell yenta to use exca registers to power 16bit cards */
socket->flags |= YENTA_16BIT_POWER_EXCA | YENTA_16BIT_POWER_DF;
+ /* Disable write buffers to prevent lockups under load with numerous
+ Cardbus cards, observed on Tecra 500CDT and reported elsewhere on the
+ net. This is not a power-on default according to the datasheet
+ but some BIOSes seem to set it. */
+ if (pci_read_config_word(socket->dev, TOPIC_PCI_CFG_PPBCN, &ppbcn) == 0
+ && socket->dev->revision <= 7
+ && (ppbcn & TOPIC_PCI_CFG_PPBCN_WBEN)) {
+ ppbcn &= ~TOPIC_PCI_CFG_PPBCN_WBEN;
+ pci_write_config_word(socket->dev, TOPIC_PCI_CFG_PPBCN, ppbcn);
+ dev_info(&socket->dev->dev, "Disabled ToPIC95 Cardbus write buffers.\n");
+ }
+
return 0;
}