On Mon, Feb 18, 2019 at 11:19:40PM +0100, Stefan Wahren wrote: > Hi, > > > Stanislaw Gruszka <sgrus...@redhat.com> hat am 18. Februar 2019 um 14:52 > > geschrieben: > > > > > > On Sat, Feb 16, 2019 at 08:17:07PM +0100, Stefan Wahren wrote: > > > this is a misunderstanding. The warning is about memory alignment to 32 > > > bit addresses, not about page alignment. This is a typical ARM > > > restriction. Maybe we need to make sure in mt76 that the DMA buffer needs > > > to be aligned. But it's also possible that the warning isn't the root > > > cause of our problem. > > > > > > > I see, it needs 4 bytes alignment . There is already dwc2 code checks > > that and allocate new buffer if the alignment is not right: > > dwc2_alloc_dma_aligned_buffer(), but it does nothing if urb->sg > > is not NULL. I thought mt76usb already provide aligned buffers, but > > looks it does not for one TX special case, which are PROBE REQUEST > > frames. Other frames are aligned by inserting L2 header pad. One > > solution for this would be just submit urb with NULL sg (same as > > Lorenzo's patches do, but still allocating buffers via buf->sg), > > but I think, you have right, we should provide 4 bytes aligned buffers > > by default as other DMA hardware may require that. I'm attaching yet > > another patch to test, which fix up alignment for PROBE REQUEST frames. > > > > > > Attached patch should fix this, plese test, thanks in advance. > > i saw Felix decided to use Lorenzo's approach. > > The patches 1,3,5 applied on today's next fixed only the warning and wifi is > still broken (authentication timeout). > > Here are the logs for multi_v7_defconfig: > https://gist.github.com/lategoodbye/0a7c5cea7dbf25d0de7944c05d229d79
It would be interesting why urb->num_sgs = 0 & urb->sg cause the troubles. This is how usb_sg_init() submit urbs for sg_tablesize = 0 controllers. So either are there are some requirement on urb->sg mapped via dma_map_page() (which mt76usb does not meet) not needed for urb->transfer_buffer mapped via dma_map_single() or there is something wrong in dwc2 with sg and this driver will not work with urb_sg_init() as well. I don't have hardware to investigate this and don't want to bother you with more patches. > > > Anyway i tested the following patch combinations against next with the > > > same results as 1,2,3 (no wifi, alignment warning): > > > 1,3 > > > 1,2,3,4 > > > > I noticed on my setup that patch 4 can cause troubles, but still > > device is workable here on my PC machines. > > > > > > > Btw i can confirm a regression was introduced after 4.19, because in > > > > > 4.19 there was no firmware timeout but even no working wifi: > > > > > > > > You ment 'no working wifi' or 'working wifi'? > > > > > > Wifi is broken in 4.19, 4.20, 5.0 and next. It only worked with Lorenzo's > > > SG avoid patches so far. Btw the regression (firmware timeout) started in > > > 4.20. I also tested it today. > > > > That somewhat strange because 4.19 mt76x0u does not use SG. > > On 4.19 there is phy calibration bug fixed in 4.19.5: > > Sorry for being inprecise. I was talking about the branches not the exact > tags. I tested 4.19.23 without luck. In github link you provided someone report mt76x0u working on 4.19 with dwc_otg with disabled FIQ irq, so perhaps this is due to bug in dwc2 fixed in -next but not backported to 4.19. > Many thanks anyway Thanks for testing! Stanislaw
