From 2c5608404e66047bbcd9b7788e7f3ee2555c8639 Mon Sep 17 00:00:00 2001 From: Abhay Salunke Date: Sat, 14 Jan 2006 13:21:14 -0800 Subject: [PATCH] [PATCH] dell_rbu: fix Bug 5854 This fixes http://bugzilla.kernel.org/show_bug.cgi?id=5854 Root cause: The dell_rbu driver creates entries in /sys/class/firmware/dell_rbu/ by calling request_firmware_nowait (without hotplug ) this function inturn starts a kernel thread which creates the entries in /sys/class/firmware/dell_rbu/loading , data and the thread waits on the user action to return control back to the callback fucntion of dell_rbu. The thread calls wait_on_completion which puts it in a D state until the user action happens. If there is no user action happening the load average goes up as the thread D state is taken in to account. Also after downloading the BIOS image the enrties go away momentarily but they are recreated from the callback function in dell_rbu. This causes the thread to get recreated causing the load average to permenently stay around 1. Fix: The dell_rbu also creates the entry /sys/devices/platform/dell_rbu/image_type at driver load time. The image type by default is mono if required the user can echo packet to image_type to make the BIOS update mechanism using packets. Also by echoing init in to image_type the /sys/class/firmware/dell_rbu entries can be created. The driver code was changed to not create /sys/class/firmware/dell_rbu entries during load time, and also to not create the above entries from the callback function. The entries are only created by echoing init to /sys/devices/platform/dell_rbu/image_type The user now needs to create the entries to download the image monolithic or packet. This fixes the issue since the kernel thread only is created when ever the user is ready to download the BIOS image; this minimizes the life span of the kernel thread and the load average goes back to normal. Signed off by Abhay Salunke Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/firmware/dell_rbu.c | 26 ++++---------------------- 1 file changed, 4 insertions(+), 22 deletions(-) diff --git a/drivers/firmware/dell_rbu.c b/drivers/firmware/dell_rbu.c index dfedb777d8..fdb8b042e6 100644 --- a/drivers/firmware/dell_rbu.c +++ b/drivers/firmware/dell_rbu.c @@ -49,7 +49,7 @@ MODULE_AUTHOR("Abhay Salunke "); MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems"); MODULE_LICENSE("GPL"); -MODULE_VERSION("3.1"); +MODULE_VERSION("3.2"); #define BIOS_SCAN_LIMIT 0xffffffff #define MAX_IMAGE_LENGTH 16 @@ -564,12 +564,10 @@ static ssize_t read_rbu_data(struct kobject *kobj, char *buffer, static void callbackfn_rbu(const struct firmware *fw, void *context) { - int rc = 0; + rbu_data.entry_created = 0; - if (!fw || !fw->size) { - rbu_data.entry_created = 0; + if (!fw || !fw->size) return; - } spin_lock(&rbu_data.lock); if (!strcmp(image_type, "mono")) { @@ -592,15 +590,6 @@ static void callbackfn_rbu(const struct firmware *fw, void *context) } else pr_debug("invalid image type specified.\n"); spin_unlock(&rbu_data.lock); - - rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG, - "dell_rbu", &rbu_device->dev, &context, callbackfn_rbu); - if (rc) - printk(KERN_ERR - "dell_rbu:%s request_firmware_nowait failed" - " %d\n", __FUNCTION__, rc); - else - rbu_data.entry_created = 1; } static ssize_t read_rbu_image_type(struct kobject *kobj, char *buffer, @@ -735,14 +724,7 @@ static int __init dcdrbu_init(void) sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_packet_size_attr); - rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG, - "dell_rbu", &rbu_device->dev, &context, callbackfn_rbu); - if (rc) - printk(KERN_ERR "dell_rbu:%s:request_firmware_nowait" - " failed %d\n", __FUNCTION__, rc); - else - rbu_data.entry_created = 1; - + rbu_data.entry_created = 0; return rc; } -- 2.39.5