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>

diff --git a/drivers/staging/greybus/fw-download.c b/drivers/staging/greybus/fw-download.c
index 0ebea37e6778b7be743e709b5293e36311eadbe7..42cbbf4ac0773c139f781cad2d95711450396a4d 100644 (file)
--- a/drivers/staging/greybus/fw-download.c
+++ b/drivers/staging/greybus/fw-download.c
@@ -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);
        }