Subject: Make b43 driver fall back gracefully to PIO mode after fatal DMA errors
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Fri, 26 Feb 2010 10:34:27 -0800 (PST)
This makes the b43 driver just automatically fall back to PIO mode when
DMA doesn't work.
The driver already told the user to do it, so rather than have the user
reload the module with a new flag, just make the driver do it
automatically. We keep the message as an indication that something is
wrong, but now just automatically fall back to the hopefully working PIO
case.
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
---
John,
This version will work with wireless-testing.
Larry
---
Index: wireless-testing/drivers/net/wireless/b43/Kconfig
===================================================================
--- wireless-testing.orig/drivers/net/wireless/b43/Kconfig
+++ wireless-testing/drivers/net/wireless/b43/Kconfig
@@ -3,7 +3,6 @@ config B43
depends on SSB_POSSIBLE && MAC80211 && HAS_DMA
select SSB
select FW_LOADER
- select SSB_BLOCKIO
---help---
b43 is a driver for the Broadcom 43xx series wireless devices.
@@ -79,6 +78,14 @@ config B43_SDIO
If unsure, say N.
+#Data transfers to the device via PIO. We want it as a fallback even
+# if we can do DMA.
+config B43_PIO
+ bool
+ depends on B43
+ select SSB_BLOCKIO
+ default y
+
config B43_NPHY
bool "Pre IEEE 802.11n support (BROKEN)"
depends on B43 && EXPERIMENTAL && BROKEN
@@ -130,4 +137,12 @@ config B43_DEBUG
for production use.
Only say Y, if you are debugging a problem in the b43 driver sourcecode.
-
+config B43_FORCE_PIO
+ bool "Force usage of PIO instead of DMA"
+ depends on B43 && B43_DEBUG
+ ---help---
+ This will disable DMA and always enable PIO instead.
+
+ Say N!
+ This is only for debugging the PIO engine code. You do
+ _NOT_ want to enable this.
Index: wireless-testing/drivers/net/wireless/b43/main.c
===================================================================
--- wireless-testing.orig/drivers/net/wireless/b43/main.c
+++ wireless-testing/drivers/net/wireless/b43/main.c
@@ -107,9 +107,9 @@ int b43_modparam_verbose = B43_VERBOSITY
module_param_named(verbose, b43_modparam_verbose, int, 0644);
MODULE_PARM_DESC(verbose, "Log message verbosity: 0=error, 1=warn, 2=info(default), 3=debug");
-static int modparam_pio;
-module_param_named(pio, modparam_pio, int, 0444);
-MODULE_PARM_DESC(pio, "enable(1) / disable(0) PIO mode");
+int b43_modparam_pio = B43_PIO_DEFAULT;
+module_param_named(pio, b43_modparam_pio, int, 0644);
+MODULE_PARM_DESC(pio, "Use PIO accesses by default: 0=DMA, 1=PIO");
static const struct ssb_device_id b43_ssb_tbl[] = {
SSB_DEVICE(SSB_VENDOR_BROADCOM, SSB_DEV_80211, 5),
@@ -1804,8 +1804,9 @@ static void b43_do_interrupt_thread(stru
dma_reason[4], dma_reason[5]);
b43err(dev->wl, "This device does not support DMA "
"on your system. Please use PIO instead.\n");
- b43err(dev->wl, "Unload the b43 module and reload "
- "with 'pio=1'\n");
+ /* Fall back to PIO transfers if we get fatal DMA errors! */
+ dev->use_pio = 1;
+ b43_controller_restart(dev, "DMA error");
return;
}
if (merged_dma_reason & B43_DMAIRQ_NONFATALMASK) {
@@ -4357,7 +4358,7 @@ static int b43_wireless_core_init(struct
if ((dev->dev->bus->bustype == SSB_BUSTYPE_PCMCIA) ||
(dev->dev->bus->bustype == SSB_BUSTYPE_SDIO) ||
- modparam_pio) {
+ dev->use_pio) {
dev->__using_pio_transfers = 1;
err = b43_pio_init(dev);
} else {
@@ -4824,6 +4825,7 @@ static int b43_one_core_attach(struct ss
if (!wldev)
goto out;
+ wldev->use_pio = b43_modparam_pio;
wldev->dev = dev;
wldev->wl = wl;
b43_set_status(wldev, B43_STAT_UNINIT);
--
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