Ryan, thanks for this patch. Could you add a "Signed-off-by" line as specified in Documentation/SubmittingPatches, please, so that I can pick it up and push it upstream? Thanks!
Dominik
On Sun, Jan 25, 2015 at 04:07:09PM -0800, Ryan C. Underwood wrote:
> From: Ryan Underwood <neme...@icequake.net>
>
> 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. Originally posted to
> https://bugzilla.kernel.org/show_bug.cgi?id=55961
> ---
> drivers/pcmcia/topic.h | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/pcmcia/topic.h b/drivers/pcmcia/topic.h
> index 615a45a..582688fe 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;
> }
>
> --
> 1.9.1
>
> --
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