On 3/23/2018 12:20 PM, David Miller wrote: > From: Sinan Kaya <okaya@xxxxxxxxxxxxxx> > Date: Thu, 22 Mar 2018 13:10:00 -0400 > >> Code includes wmb() followed by writel(). writel() already has a >> barrier on some architectures like arm64. > ... >> @@ -4155,7 +4155,7 @@ netdev_tx_t bnx2x_start_xmit(struct sk_buff *skb, struct net_device *dev) >> txdata->tx_db.data.prod += nbd; >> barrier(); >> >> - DOORBELL(bp, txdata->cid, txdata->tx_db.raw); >> + DOORBELL_RELAXED(bp, txdata->cid, txdata->tx_db.raw); >> >> mmiowb(); > ... >> @@ -2592,7 +2592,7 @@ static int bnx2x_run_loopback(struct bnx2x *bp, int loopback_mode) >> >> txdata->tx_db.data.prod += 2; >> barrier(); >> - DOORBELL(bp, txdata->cid, txdata->tx_db.raw); >> + DOORBELL_RELAXED(bp, txdata->cid, txdata->tx_db.raw); > > These are compiler barriers being used here, not wmb(). > > Look, if I can't see a clear: > > wmb() > writel() > > sequence in the patch hunks, I am going to keep pushing back on > these changes. Sorry, you got me confused now. If you look at the code closer, you'll see this. wmb(); txdata->tx_db.data.prod += nbd; barrier(); DOORBELL(bp, txdata->cid, txdata->tx_db.raw); and you also asked me to rename DOORBELL to DOORBELL_RELAXED() to make it obvious that we have a relaxed operator inside the macro. Did I miss something? of course, treating barrier() universally as a write barrier is wrong. > > Thank you. > -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
