From: Arnd Bergmann Date: Tue, 21 Aug 2007 02:06:22 +0000 (+0800) Subject: [POWERPC] spufs: Fix update of mailbox status register during backed wbox write X-Git-Tag: v2.6.23-rc5~43^2~3 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=62ee68e3bcb0d056aae5b36dea0388ca25572cdf;p=linux-2.6 [POWERPC] spufs: Fix update of mailbox status register during backed wbox write When a process writes into the inbound spu mailbox (wbox) while the context is saved, we accidentally break the contents of the mb_stat_R register by clearing other entries of the mailbox status register. This can cause the user side to hang. This change fixes the problem by only altering the appropriate bits of the mailbox status register during a backing-store write. Signed-off-by: Arnd Bergmann Signed-off-by: Jeremy Kerr Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/platforms/cell/spufs/backing_ops.c b/arch/powerpc/platforms/cell/spufs/backing_ops.c index 07a0e815ab..ec01214e51 100644 --- a/arch/powerpc/platforms/cell/spufs/backing_ops.c +++ b/arch/powerpc/platforms/cell/spufs/backing_ops.c @@ -162,7 +162,8 @@ static int spu_backing_wbox_write(struct spu_context *ctx, u32 data) BUG_ON(avail != (4 - slot)); ctx->csa.spu_mailbox_data[slot] = data; ctx->csa.spu_chnlcnt_RW[29] = ++slot; - ctx->csa.prob.mb_stat_R = (((4 - slot) & 0xff) << 8); + ctx->csa.prob.mb_stat_R &= ~(0x00ff00); + ctx->csa.prob.mb_stat_R |= (((4 - slot) & 0xff) << 8); gen_spu_event(ctx, MFC_SPU_MAILBOX_WRITTEN_EVENT); ret = 4; } else {