* Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx> [191021 01:40]: > Hi Tony, > > On Thu, Oct 3, 2019 at 10:39 AM Yegor Yefremov > <yegorslists@xxxxxxxxxxxxxx> wrote: > > > > Hi Tony, > > > > On Wed, Oct 2, 2019 at 6:52 PM Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > > > > > * Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx> [191002 06:57]: > > > > On Wed, Oct 2, 2019 at 12:03 AM Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > > > > The other way to fix this would be to just wake up cpp41 in > > > > > cppi41_dma_prep_slave_sg() and return NULL so that we can > > > > > have musb_ep_program() continue with PIO while cppi41 is > > > > > asleep. > > > > > > > > > > Anyways, care to try it out and see if it fixes your issue? > > > > > > > > The fix is working but on the first invocation, I get this output > > > > (minicom provokes the same output): > > > > > > > # serialtest.py -c 2 /dev/ttyUSB0 /dev/ttyUSB0 > > > ... > > > > [ 210.940612] [<c065fc94>] (__rpm_callback) from [<c065fd60>] > > > > (rpm_callback+0x20/0x80) > > > > [ 210.948402] [<c065fd60>] (rpm_callback) from [<c065f7cc>] > > > > (rpm_resume+0x468/0x7a0) > > > > [ 210.956018] [<c065f7cc>] (rpm_resume) from [<c065fb50>] > > > > (__pm_runtime_resume+0x4c/0x64) > > > > [ 210.964086] [<c065fb50>] (__pm_runtime_resume) from [<bf020940>] > > > > (cppi41_dma_prep_slave_sg+0x20/0xfc [cppi41]) > > > > > > OK so that won't work, thanks for testing. Here's the alternative > > > patch to try along the lines described above that just wakes up > > > cppi41 and returns NULL so musb_ep_program() can continue with PIO > > > until cppi41 is awake. > > > > I'm out of the office for some weeks and don't have access to my hw. > > I'll make the test as soon as I'm back. > > I've tested your patch with both systems (with and without a hub) and > everything is working as expected. OK good to hear, I just sent it out with a proper description as: [PATCH] dmaengine: cppi41: Fix issue with musb and ftdi uart Regards, Tony