Christian Borntraeger wrote: > Hmmm, if we are ok with having both options, we should let the hvc backend > decide if it wants to drain or to discard. > > If we just busy loop, it actually does not matter how we let hvc_console > react > on 0, as long as we adopt all backends to use that interface consistent. > > On the other hand, backends might want to do special magic on congestion so I > personally tend to let the backend loop instead of hvc_console. But I am > really > not sure.
The reason that we're asking for this change is that I have an hvc client driver that drops characters during heavy printk() output. hvc calls my driver, but the output buffer is still full, so the driver just returns 0. If I add a spin-loop in the driver, then we don't need to change hvc, but now the driver is blocking during user-space print operations (via hvc_write and hvc_push). -- Timur Tabi Linux kernel developer at Freescale _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
