[PATCH 2/5] spufs: fix MFC command queue purge

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Benjamin Herrenschmidt <[email protected]>

In the context save/restore code, the SPU MFC command queue purge
code has a bug:

static inline void wait_purge_complete(struct spu_state *csa, struct
				       spu *spu)
{
    struct spu_priv2 __iomem *priv2 = spu->priv2;

    /* Save, Step 28:
     *     Poll MFC_CNTL[Ps] until value '11' is
     *     read
     *      (purge complete).
     */
    POLL_WHILE_FALSE(in_be64(&priv2->mfc_control_RW)
		     & MFC_CNTL_PURGE_DMA_COMPLETE);
}

This will exit as soon as _one_ of the 2 bits that compose
MFC_CNTL_PURGE_DMA_COMPLETE is set, and one of them happens to be
"purge in progress"...  which means that we'll happily continue
restoring the MFC while it's being purged at the same time.

Signed-off-by: Benjamin Herrenschmidt <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Index: linus-2.6/arch/powerpc/platforms/cell/spufs/switch.c
===================================================================
--- linus-2.6.orig/arch/powerpc/platforms/cell/spufs/switch.c
+++ linus-2.6/arch/powerpc/platforms/cell/spufs/switch.c
@@ -464,7 +464,8 @@ static inline void wait_purge_complete(s
 	 *     Poll MFC_CNTL[Ps] until value '11' is read
 	 *     (purge complete).
 	 */
-	POLL_WHILE_FALSE(in_be64(&priv2->mfc_control_RW) &
+	POLL_WHILE_FALSE((in_be64(&priv2->mfc_control_RW) &
+			 MFC_CNTL_PURGE_DMA_STATUS_MASK) ==
 			 MFC_CNTL_PURGE_DMA_COMPLETE);
 }
 
@@ -1028,7 +1029,8 @@ static inline void wait_suspend_mfc_comp
 	 * Restore, Step 47.
 	 *     Poll MFC_CNTL[Ss] until 11 is returned.
 	 */
-	POLL_WHILE_FALSE(in_be64(&priv2->mfc_control_RW) &
+	POLL_WHILE_FALSE((in_be64(&priv2->mfc_control_RW) &
+			 MFC_CNTL_SUSPEND_DMA_STATUS_MASK) ==
 			 MFC_CNTL_SUSPEND_COMPLETE);
 }
 

--

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux