Commit 2fb22a80 authored by Ryan Underwood's avatar Ryan Underwood Committed by Dominik Brodowski
Browse files

Disable write buffering on Toshiba ToPIC95 

Disable write buffering on the Toshiba ToPIC95 if it is enabled by
somebody (it is not supposed to be a power-on default according to
the datasheet). On the ToPIC95, practically no 32-bit Cardbus card
will work under heavy load without locking up the whole system if
this is left enabled. I tried about a dozen. It does not affect
16-bit cards. This is similar to the O2 bugs in early controller
revisions it seems.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=55961


Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarRyan C. Underwood <nemesis@icequake.net>
Signed-off-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent f2e6cf76

drivers/pcmcia/topic.h

+16 −0
Original line number Original line Diff line number Diff line
@@ -104,6 +104,9 @@ 
#define TOPIC_EXCA_IF_CONTROL		0x3e	/* 8 bit */

#define TOPIC_EXCA_IF_CONTROL		0x3e	/* 8 bit */

#define TOPIC_EXCA_IFC_33V_ENA		0x01

#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)

static void topic97_zoom_video(struct pcmcia_socket *sock, int onoff)

{

{

	struct yenta_socket *socket = container_of(sock, struct yenta_socket, socket);

	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)

static int topic95_override(struct yenta_socket *socket)

{

{

	u8 fctrl;

	u8 fctrl;

	u16 ppbcn;





	/* enable 3.3V support for 16bit cards */

	/* enable 3.3V support for 16bit cards */

	fctrl = exca_readb(socket, TOPIC_EXCA_IF_CONTROL);

	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 */

	/* tell yenta to use exca registers to power 16bit cards */

	socket->flags |= YENTA_16BIT_POWER_EXCA | YENTA_16BIT_POWER_DF;

	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;

	return 0;

}

}

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