On Tue, May 15, 2018 at 2:21 AM, Vinod <vkoul@xxxxxxxxxx> wrote: > > For Pause/resume data loss is _not_ expected. > >> > and some of the 8250 drivers like 8250_dw.c set a maxburst > 1. If it >> > can't count on the pause/residue/terminate working without data loss >> > then it is just broken. As is the 8250_omap.c driver. Is the >> > description of dmaengine_pause in the documentation of "This pauses >> > activity on the DMA channel without data loss" to be interpreted as >> > "as long as you resume afterwards"? >> >> I assume that this requirement is for both - resuming and terminating. > > Terminate is abort, data loss may happen here. Wait, are you saying if you do dma pause read residue dma terminate then it is acceptable for there to be data loss, because it can be blamed on the terminate? In that case the usage of dmaengine in all the 8250 serial drivers is broken. Every time there is a break in the incoming rx data, the 8250 driver does pause/residue/terminate which could potentially cause data from the incoming data stream to be dropped. -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
