Return-path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:62943 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966044Ab0BZU3B (ORCPT ); Fri, 26 Feb 2010 15:29:01 -0500 Date: Fri, 26 Feb 2010 14:28:58 -0600 From: Larry Finger To: John W Linville , Michael Buesch Cc: torvalds@linux-foundation.org, bcm43xx-dev@lists.berlios.de, linux-wireless@vger.kernel.org Subject: [PATCH] b43: Make driver fall back gracefully to PIO mode after fatal DMA errors Message-ID: <4b882f0a.mh6Uqo07p1AwjuBv%Larry.Finger@lwfinger.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Subject: Make b43 driver fall back gracefully to PIO mode after fatal DMA errors From: Linus Torvalds 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 --- 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);