USB: ehci refcounts work on ppc7448 (9c033e81) · Commits · 戴 / test

drivers/usb/host/ehci-mem.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -64,9 +64,8 @@ static inline void ehci_qtd_free (struct ehci_hcd ehci, struct ehci_qtd qtd)
		}


		static void qh_destroy (struct kref *kref)
		static void qh_destroy(struct ehci_qh *qh)
		{
		struct ehci_qh *qh = container_of(kref, struct ehci_qh, kref);
		struct ehci_hcd *ehci = qh->ehci;

		/* clean qtds first, and know this is not linked */
		@@ -90,7 +89,7 @@ static struct ehci_qh ehci_qh_alloc (struct ehci_hcd ehci, gfp_t flags)
		return qh;

		memset (qh, 0, sizeof *qh);
		kref_init(&qh->kref);
		qh->refcount = 1;
		qh->ehci = ehci;
		qh->qh_dma = dma;
		// INIT_LIST_HEAD (&qh->qh_list);
		@@ -112,13 +111,15 @@ static struct ehci_qh ehci_qh_alloc (struct ehci_hcd ehci, gfp_t flags)
		/* to share a qh (cpu threads, or hc) */
		static inline struct ehci_qh qh_get (struct ehci_qh qh)
		{
		kref_get(&qh->kref);
		WARN_ON(!qh->refcount);
		qh->refcount++;
		return qh;
		}

		static inline void qh_put (struct ehci_qh *qh)
		{
		kref_put(&qh->kref, qh_destroy);
		if (!--qh->refcount)
		qh_destroy(qh);
		}

		/-------------------------------------------------------------------------/

+8 −1

Original line number	Diff line number	Diff line
		@@ -457,7 +457,14 @@ struct ehci_qh {
		struct ehci_qh reclaim; / next to reclaim */

		struct ehci_hcd *ehci;
		struct kref kref;

		/*
		* Do NOT use atomic operations for QH refcounting. On some CPUs
		* (PPC7448 for example), atomic operations cannot be performed on
		* memory that is cache-inhibited (i.e. being used for DMA).
		* Spinlocks are used to protect all QH fields.
		*/
		u32 refcount;
		unsigned stamp;

		u8 qh_state;