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[POWERPC] spufs: fix MFC command queue purge

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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 <benh@kernel.crashing.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Benjamin Herrenschmidt 2006-06-23 20:57:48 +02:00 committed by Paul Mackerras
parent 23cc770107
commit 910ab66b1c
1 changed files with 4 additions and 2 deletions
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6
arch/powerpc/platforms/cell/spufs/switch.c
View File

@ -464,7 +464,8 @@ static inline void wait_purge_complete(struct spu_state *csa, struct spu *spu)
* 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_complete(struct spu_state *csa,
* 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);
}