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greybus: fw-download: Replace timer with delayed-work 

The timeout-handlers need to call routines that can sleep and those
can't be called from interrupt context. The timer-handler is called in
interrupt context and so will hit a BUG() in vmalloc.c.

This patch moves away from timers to delayed-work, whose timeout handler
gets called in process context and can call the sleep-able routines
safely.

Note that this issue wasn't hit earlier when the initial patch for
timeouts was implemented due to some issues in the build arche_420. But
with the new build arche_440, the BUG started crashing the phone on
timeouts and so this fix is required.

Tested on EVT 1.5 by triggering fake timeouts, by not sending
release-firmware request for example. This is tested with build
arche_440.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Viresh Kumar 2016-05-09 10:59:01 +05:30 committed by Greg Kroah-Hartman
parent a956d939af
commit c6cc8e73eb
1 changed files with 12 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/staging/greybus/fw-download.c
View File

@ -10,7 +10,7 @@
#include <linux/firmware.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include "firmware.h"
#include "greybus.h"
@ -29,7 +29,7 @@ struct fw_request {
const struct firmware *fw;
struct list_head node;
struct timer_list timer;
struct delayed_work dwork;
/* Timeout, in jiffies, within which the firmware shall download */
unsigned long release_timeout_j;
struct kref kref;
@ -129,9 +129,10 @@ static void free_firmware(struct fw_download *fw_download,
put_fw_req(fw_req);
}
static void fw_request_timedout(unsigned long data)
static void fw_request_timedout(struct work_struct *work)
{
struct fw_request *fw_req = (struct fw_request *)data;
struct delayed_work *dwork = to_delayed_work(work);
struct fw_request *fw_req = container_of(dwork, struct fw_request, dwork);
struct fw_download *fw_download = fw_req->fw_download;
dev_err(fw_download->parent,
@ -207,11 +208,8 @@ static struct fw_request *find_firmware(struct fw_download *fw_download,
req_count = DIV_ROUND_UP(fw_req->fw->size, MIN_FETCH_SIZE);
fw_req->release_timeout_j = jiffies + req_count * NEXT_REQ_TIMEOUT_J;
init_timer(&fw_req->timer);
fw_req->timer.function = fw_request_timedout;
fw_req->timer.expires = jiffies + NEXT_REQ_TIMEOUT_J;
fw_req->timer.data = (unsigned long)fw_req;
add_timer(&fw_req->timer);
INIT_DELAYED_WORK(&fw_req->dwork, fw_request_timedout);
schedule_delayed_work(&fw_req->dwork, NEXT_REQ_TIMEOUT_J);
return fw_req;
@ -300,8 +298,8 @@ static int fw_download_fetch_firmware(struct gb_operation *op)
return -EINVAL;
}
/* Make sure timer handler isn't running in parallel */
del_timer_sync(&fw_req->timer);
/* Make sure work handler isn't running in parallel */
cancel_delayed_work_sync(&fw_req->dwork);
/* We timed-out before reaching here ? */
if (fw_req->disabled) {
@ -344,7 +342,7 @@ static int fw_download_fetch_firmware(struct gb_operation *op)
size);
/* Refresh timeout */
mod_timer(&fw_req->timer, jiffies + NEXT_REQ_TIMEOUT_J);
schedule_delayed_work(&fw_req->dwork, NEXT_REQ_TIMEOUT_J);
put_fw:
put_fw_req(fw_req);
@ -377,7 +375,7 @@ static int fw_download_release_firmware(struct gb_operation *op)
return -EINVAL;
}
del_timer_sync(&fw_req->timer);
cancel_delayed_work_sync(&fw_req->dwork);
free_firmware(fw_download, fw_req);
put_fw_req(fw_req);
@ -459,7 +457,7 @@ void gb_fw_download_connection_exit(struct gb_connection *connection)
/* Release pending firmware packages */
list_for_each_entry_safe(fw_req, tmp, &fw_download->fw_requests, node) {
del_timer_sync(&fw_req->timer);
cancel_delayed_work_sync(&fw_req->dwork);
free_firmware(fw_download, fw_req);
put_fw_req(fw_req);
}