Commit c6cc8e73 authored by Viresh Kumar's avatar Viresh Kumar Committed by Greg Kroah-Hartman
Browse files

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: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
parent a956d939

drivers/staging/greybus/fw-download.c

+12 −14
Original line number Diff line number Diff line
@@ -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);

	}