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Revert "usb: host: ehci: Use dma_pool_zalloc()"
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 4 May 2018 21:35:12 +0000 (14:35 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 4 May 2018 21:35:12 +0000 (14:35 -0700)
This reverts commit 22072e83ebd510fb6a090aef9d65ccfda9b1e7e4 as it is
broken.

Alan writes:
What you can't see just from reading the patch is that in both
cases (ehci->itd_pool and ehci->sitd_pool) there are two
allocation paths -- the two branches of an "if" statement -- and
only one of the paths calls dma_pool_[z]alloc.  However, the
memset is needed for both paths, and so it can't be eliminated.
Given that it must be present, there's no advantage to calling
dma_pool_zalloc rather than dma_pool_alloc.

Reported-by: Erick Cafferata <erick@cafferata.me>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/ehci-mem.c
drivers/usb/host/ehci-sched.c

index 4c6c08b..21307d8 100644 (file)
@@ -73,9 +73,10 @@ static struct ehci_qh *ehci_qh_alloc (struct ehci_hcd *ehci, gfp_t flags)
        if (!qh)
                goto done;
        qh->hw = (struct ehci_qh_hw *)
-               dma_pool_zalloc(ehci->qh_pool, flags, &dma);
+               dma_pool_alloc(ehci->qh_pool, flags, &dma);
        if (!qh->hw)
                goto fail;
+       memset(qh->hw, 0, sizeof *qh->hw);
        qh->qh_dma = dma;
        // INIT_LIST_HEAD (&qh->qh_list);
        INIT_LIST_HEAD (&qh->qtd_list);
index 28e2a33..e56db44 100644 (file)
@@ -1287,7 +1287,7 @@ itd_urb_transaction(
                } else {
  alloc_itd:
                        spin_unlock_irqrestore(&ehci->lock, flags);
-                       itd = dma_pool_zalloc(ehci->itd_pool, mem_flags,
+                       itd = dma_pool_alloc(ehci->itd_pool, mem_flags,
                                        &itd_dma);
                        spin_lock_irqsave(&ehci->lock, flags);
                        if (!itd) {
@@ -1297,6 +1297,7 @@ itd_urb_transaction(
                        }
                }
 
+               memset(itd, 0, sizeof(*itd));
                itd->itd_dma = itd_dma;
                itd->frame = NO_FRAME;
                list_add(&itd->itd_list, &sched->td_list);
@@ -2080,7 +2081,7 @@ sitd_urb_transaction(
                } else {
  alloc_sitd:
                        spin_unlock_irqrestore(&ehci->lock, flags);
-                       sitd = dma_pool_zalloc(ehci->sitd_pool, mem_flags,
+                       sitd = dma_pool_alloc(ehci->sitd_pool, mem_flags,
                                        &sitd_dma);
                        spin_lock_irqsave(&ehci->lock, flags);
                        if (!sitd) {
@@ -2090,6 +2091,7 @@ sitd_urb_transaction(
                        }
                }
 
+               memset(sitd, 0, sizeof(*sitd));
                sitd->sitd_dma = sitd_dma;
                sitd->frame = NO_FRAME;
                list_add(&sitd->sitd_list, &iso_sched->td_list);