usb: gadget: u_audio: remove struct uac_req

'struct uac_req' purpose is to link 'struct usb_request' to the
corresponding 'struct uac_rtd_params'. However member req is never
used. Using the context of the usb request, we can keep track of the
corresponding 'struct uac_rtd_params' just as well, without allocating
extra memory.
Acked-by: NFelipe Balbi <balbi@kernel.org>
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20210118084642.322510-4-jbrunet@baylibre.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/function/u_audio.c

@@ -23,11 +23,6 @@
 #define PRD_SIZE_MAX	PAGE_SIZE
 #define MIN_PERIODS	4
 
-struct uac_req {
-	struct uac_rtd_params *pp; /* parent param */
-	struct usb_request *req;
-};
-
 /* Runtime data params for one stream */
 struct uac_rtd_params {
 	struct snd_uac_chip *uac; /* parent chip */
@@ -41,7 +36,7 @@ struct uac_rtd_params {
 	void *rbuf;
 
 	unsigned int max_psize;	/* MaxPacketSize of endpoint */
-	struct uac_req *ureq;
+	struct usb_request **reqs;
 
 	spinlock_t lock;
 };
@@ -82,10 +77,9 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)
 	unsigned long flags, flags2;
 	unsigned int hw_ptr;
 	int status = req->status;
-	struct uac_req *ur = req->context;
 	struct snd_pcm_substream *substream;
 	struct snd_pcm_runtime *runtime;
-	struct uac_rtd_params *prm = ur->pp;
+	struct uac_rtd_params *prm = req->context;
 	struct snd_uac_chip *uac = prm->uac;
 
 	/* i/f shutting down */
@@ -339,16 +333,16 @@ static inline void free_ep(struct uac_rtd_params *prm, struct usb_ep *ep)
 	params = &audio_dev->params;
 
 	for (i = 0; i < params->req_number; i++) {
-		if (prm->ureq[i].req) {
-			if (usb_ep_dequeue(ep, prm->ureq[i].req))
-				usb_ep_free_request(ep, prm->ureq[i].req);
+		if (prm->reqs[i]) {
+			if (usb_ep_dequeue(ep, prm->reqs[i]))
+				usb_ep_free_request(ep, prm->reqs[i]);
 			/*
 			 * If usb_ep_dequeue() cannot successfully dequeue the
 			 * request, the request will be freed by the completion
 			 * callback.
 			 */
 
-			prm->ureq[i].req = NULL;
+			prm->reqs[i] = NULL;
 		}
 	}
 
@@ -377,22 +371,21 @@ int u_audio_start_capture(struct g_audio *audio_dev)
 	usb_ep_enable(ep);
 
 	for (i = 0; i < params->req_number; i++) {
-		if (!prm->ureq[i].req) {
+		if (!prm->reqs[i]) {
 			req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 			if (req == NULL)
 				return -ENOMEM;
 
-			prm->ureq[i].req = req;
-			prm->ureq[i].pp = prm;
+			prm->reqs[i] = req;
 
 			req->zero = 0;
-			req->context = &prm->ureq[i];
+			req->context = prm;
 			req->length = req_len;
 			req->complete = u_audio_iso_complete;
 			req->buf = prm->rbuf + i * ep->maxpacket;
 		}
 
-		if (usb_ep_queue(ep, prm->ureq[i].req, GFP_ATOMIC))
+		if (usb_ep_queue(ep, prm->reqs[i], GFP_ATOMIC))
 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
 	}
 
@@ -455,22 +448,21 @@ int u_audio_start_playback(struct g_audio *audio_dev)
 	usb_ep_enable(ep);
 
 	for (i = 0; i < params->req_number; i++) {
-		if (!prm->ureq[i].req) {
+		if (!prm->reqs[i]) {
 			req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 			if (req == NULL)
 				return -ENOMEM;
 
-			prm->ureq[i].req = req;
-			prm->ureq[i].pp = prm;
+			prm->reqs[i] = req;
 
 			req->zero = 0;
-			req->context = &prm->ureq[i];
+			req->context = prm;
 			req->length = req_len;
 			req->complete = u_audio_iso_complete;
 			req->buf = prm->rbuf + i * ep->maxpacket;
 		}
 
-		if (usb_ep_queue(ep, prm->ureq[i].req, GFP_ATOMIC))
+		if (usb_ep_queue(ep, prm->reqs[i], GFP_ATOMIC))
 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
 	}
 
@@ -515,9 +507,10 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
 		uac->c_prm.uac = uac;
 		prm->max_psize = g_audio->out_ep_maxpsize;
 
-		prm->ureq = kcalloc(params->req_number, sizeof(struct uac_req),
-				GFP_KERNEL);
-		if (!prm->ureq) {
+		prm->reqs = kcalloc(params->req_number,
+				    sizeof(struct usb_request *),
+				    GFP_KERNEL);
+		if (!prm->reqs) {
 			err = -ENOMEM;
 			goto fail;
 		}
@@ -537,9 +530,10 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
 		uac->p_prm.uac = uac;
 		prm->max_psize = g_audio->in_ep_maxpsize;
 
-		prm->ureq = kcalloc(params->req_number, sizeof(struct uac_req),
-				GFP_KERNEL);
-		if (!prm->ureq) {
+		prm->reqs = kcalloc(params->req_number,
+				    sizeof(struct usb_request *),
+				    GFP_KERNEL);
+		if (!prm->reqs) {
 			err = -ENOMEM;
 			goto fail;
 		}
@@ -592,8 +586,8 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
 snd_fail:
 	snd_card_free(card);
 fail:
-	kfree(uac->p_prm.ureq);
-	kfree(uac->c_prm.ureq);
+	kfree(uac->p_prm.reqs);
+	kfree(uac->c_prm.reqs);
 	kfree(uac->p_prm.rbuf);
 	kfree(uac->c_prm.rbuf);
 	kfree(uac);
@@ -615,8 +609,8 @@ void g_audio_cleanup(struct g_audio *g_audio)
 	if (card)
 		snd_card_free(card);
 
-	kfree(uac->p_prm.ureq);
-	kfree(uac->c_prm.ureq);
+	kfree(uac->p_prm.reqs);
+	kfree(uac->c_prm.reqs);
 	kfree(uac->p_prm.rbuf);
 	kfree(uac->c_prm.rbuf);
 	kfree(uac);