From: Kazunori Asayama Date: Fri, 29 Jun 2007 00:58:08 +0000 (+1000) Subject: [POWERPC] spufs: Fix lost events in poll/epoll on mfc X-Git-Tag: v2.6.23-rc1~767^2^2~57 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=933b0e35247ef0dbd1a078a0ba3705ddbbda129f;p=linux-2.6 [POWERPC] spufs: Fix lost events in poll/epoll on mfc When waiting for I/O events on mfc in an SPU context by using poll/epoll syscalls, some of the events can be lost because of wrong order of poll_wait and MFC status checks in the spufs_mfc_poll function and non-atomic update of tagwait. This fixes the problem. Signed-off-by: Kazunori Asayama Signed-off-by: Jeremy Kerr Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c index 30f7b077f3..c2814ea96a 100644 --- a/arch/powerpc/platforms/cell/spufs/file.c +++ b/arch/powerpc/platforms/cell/spufs/file.c @@ -1499,14 +1499,15 @@ static ssize_t spufs_mfc_write(struct file *file, const char __user *buffer, if (status) ret = status; } - spu_release(ctx); if (ret) - goto out; + goto out_unlock; ctx->tagwait |= 1 << cmd.tag; ret = size; +out_unlock: + spu_release(ctx); out: return ret; } @@ -1517,14 +1518,14 @@ static unsigned int spufs_mfc_poll(struct file *file,poll_table *wait) u32 free_elements, tagstatus; unsigned int mask; + poll_wait(file, &ctx->mfc_wq, wait); + spu_acquire(ctx); ctx->ops->set_mfc_query(ctx, ctx->tagwait, 2); free_elements = ctx->ops->get_mfc_free_elements(ctx); tagstatus = ctx->ops->read_mfc_tagstatus(ctx); spu_release(ctx); - poll_wait(file, &ctx->mfc_wq, wait); - mask = 0; if (free_elements & 0xffff) mask |= POLLOUT | POLLWRNORM;