Re: [PATCH 1/1 RFC] wcn36xx: fix buffer commit logic on TX path

Daniel Mack writes: > Hi Loic, > > On Wednesday, April 11, 2018 03:30 PM, Loic Poulain wrote: >>> /* Move the head of the ring to the next empty descriptor */ >>> -ch->head_blk_ctl = ctl->next; >>> +ch->head_blk_ctl = ctl_skb->next; >>> + >>> + /*

Re: [PATCH 1/1 RFC] wcn36xx: fix buffer commit logic on TX path

Hi Loic, On Wednesday, April 11, 2018 03:30 PM, Loic Poulain wrote: >> /* Move the head of the ring to the next empty descriptor */ >> -ch->head_blk_ctl = ctl->next; >> +ch->head_blk_ctl = ctl_skb->next; >> + >> + /* Commit all previous writes and set descriptors to

Re: [PATCH 1/1 RFC] wcn36xx: fix buffer commit logic on TX path

On 11 April 2018 at 15:37, Daniel Mack wrote: > Hi Loic, > > On Wednesday, April 11, 2018 03:30 PM, Loic Poulain wrote: >>> /* Move the head of the ring to the next empty descriptor */ >>> -ch->head_blk_ctl = ctl->next; >>> +ch->head_blk_ctl =

Re: [PATCH 1/1 RFC] wcn36xx: fix buffer commit logic on TX path

Hi Loic, On Wednesday, April 11, 2018 03:30 PM, Loic Poulain wrote: >> /* Move the head of the ring to the next empty descriptor */ >> -ch->head_blk_ctl = ctl->next; >> +ch->head_blk_ctl = ctl_skb->next; >> + >> + /* Commit all previous writes and set descriptors to

Re: [PATCH 1/1 RFC] wcn36xx: fix buffer commit logic on TX path

Hi Daniel, > /* Move the head of the ring to the next empty descriptor */ > -ch->head_blk_ctl = ctl->next; > +ch->head_blk_ctl = ctl_skb->next; > + > + /* Commit all previous writes and set descriptors to VALID */ > + wmb(); Is this first memory barrier really

[PATCH 1/1 RFC] wcn36xx: fix buffer commit logic on TX path

When wcn36xx_dxe_tx_frame() is entered while the device is still processing the queue asyncronously, we are racing against the firmware code with updates to the buffer descriptors. Presumably, the firmware scans the ring buffer that holds the descriptors and scans for a valid control descriptor,