Re: [PATCH 2/2] orinoco: cache downloadable firmware image in memory for use during resume

[Andrey Borzenkov <arvidjaar@mail.ru>]

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On Saturday 11 October 2008, Dave wrote:
> Andrey Borzenkov wrote:
> > orinoco: cache downloadable firmware image in memory for use during resume
> > 
> > If card is using downloadable firmware (like Agere 9.x), firmware has
> > to be reloaded during resume. It is not possible to use request_firmware
> > for that, because tasks are still frozen, so request_firmware will
> > just timeout and fail. So cache firmware image in memory for later
> > reuse in ->resume method.
> > 
> > Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru>
> > 
> > ---
> > 
> > Unfortunately this is the only way to do it given current infrastructure.
> > I think that extra memory cost (~60kb) does not warrant anything more
> > sophisticated - even if this is possible. Also users not using dowloadable
> > firmware won't be penalized at all.
> 
> Spectrum_cs has had firmware download for a while. It achieves the firmware reload on resume by doing schedule_work(&priv->reset_work).
> 
> Would the same work for orinoco_cs?
> 

I think it could result in hard to trace race condition, because you really
have no way to synchronize it with unfreezing of udev.

> If not, is there a way to avoid the caching when you've got the firmware built into the kernel image?
> 

Actually, yes. Patch attached. It needs some touching when (if) we start
supporting AP mode; right now only one kind of image is ever loaded.

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Subject: [PATCH] orinoco: cache downloadable firmware image in memory for use during resume
From: Andrey Borzenkov <arvidjaar@mail.ru>

If card is using downloadable firmware (like Agere 9.x), firmware has
to be reloaded during resume. It is not possible to use request_firmware
for that, because tasks are still frozen, so request_firmware will
just timeout and fail. So cache firmware image in memory for later
reuse in ->resume method.

Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru>

---

 drivers/net/wireless/orinoco.c |   28 +++++++++++++++++++++-------
 drivers/net/wireless/orinoco.h |    5 +++++
 2 files changed, 26 insertions(+), 7 deletions(-)


diff --git a/drivers/net/wireless/orinoco.c b/drivers/net/wireless/orinoco.c
index 722619c..8a15230 100644
--- a/drivers/net/wireless/orinoco.c
+++ b/drivers/net/wireless/orinoco.c
@@ -487,12 +487,17 @@ orinoco_dl_firmware(struct orinoco_private *priv,
 	if (err)
 		goto free;
 
-	err = request_firmware(&fw_entry, firmware, priv->dev);
-	if (err) {
-		printk(KERN_ERR "%s: Cannot find firmware %s\n",
-		       dev->name, firmware);
-		err = -ENOENT;
-		goto free;
+	if (priv->cached_fw)
+		fw_entry = priv->cached_fw;
+	else {
+		err = request_firmware(&fw_entry, firmware, priv->dev);
+		if (err) {
+			printk(KERN_ERR "%s: Cannot find firmware %s\n",
+			       dev->name, firmware);
+			err = -ENOENT;
+			goto free;
+		}
+		priv->cached_fw = fw_entry;
 	}
 
 	hdr = (const struct orinoco_fw_header *) fw_entry->data;
@@ -535,7 +540,11 @@ orinoco_dl_firmware(struct orinoco_private *priv,
 	       dev->name, hermes_present(hw));
 
 abort:
-	release_firmware(fw_entry);
+	/* In case of error, assume firmware was bogus and release it */
+	if (err) {
+		priv->cached_fw = NULL;
+		release_firmware(fw_entry);
+	}
 
 free:
 	kfree(pda);
@@ -3534,6 +3543,8 @@ struct net_device
 	netif_carrier_off(dev);
 	priv->last_linkstatus = 0xffff;
 
+	priv->cached_fw = NULL;
+
 	return dev;
 }
 
@@ -3545,6 +3556,9 @@ void free_orinocodev(struct net_device *dev)
 	 * when we call tasklet_kill it will run one final time,
 	 * emptying the list */
 	tasklet_kill(&priv->rx_tasklet);
+	if (priv->cached_fw)
+		release_firmware(priv->cached_fw);
+	priv->cached_fw = NULL;
 	priv->wpa_ie_len = 0;
 	kfree(priv->wpa_ie);
 	orinoco_mic_free(priv);
diff --git a/drivers/net/wireless/orinoco.h b/drivers/net/wireless/orinoco.h
index 981570b..8c29538 100644
--- a/drivers/net/wireless/orinoco.h
+++ b/drivers/net/wireless/orinoco.h
@@ -66,6 +66,8 @@ struct orinoco_rx_data {
 	struct list_head list;
 };
 
+struct firmware;
+
 struct orinoco_private {
 	void *card;	/* Pointer to card dependent structure */
 	struct device *dev;
@@ -164,6 +166,9 @@ struct orinoco_private {
 	unsigned int wpa_enabled:1;
 	unsigned int tkip_cm_active:1;
 	unsigned int key_mgmt:3;
+
+	/* Cached in memory firmware to use in ->resume */
+	const struct firmware *cached_fw;
 };
 
 #ifdef ORINOCO_DEBUG

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