Larry Finger <larry.fin...@lwfinger.net> writes: > From: Vincent Fann <vincent_f...@realtek.com> > > Several of these drivers have there TX randomly blocked for 3~5 seconds while > measuring tx throughput (iperf). The root couse happens in rtl_pci_flush(). > The function uses a while-loop to wait for TX queue length to decrease to 0. > The TX queue length counts the number of packets that are queued in the > driver. > The driver relys on the TX OK interrupt to return skb and reduce TX queue > length. > > The interrupt subroutine disables interupts, reads the interrupt registers, > and > then clears the registers in the beginning of _rtl_pci_interrupt(). After all > interupts process are finished, the driver invokes enable_interrupt() to > enable > interupts. This behavior is normal for an interrupt subroutine. > > But enable_interrupt() invokes clear_interrupt() again. This unexpected > interrupt > clearing may cleari me fresh TX OK interrupts. These missing interrupts cause > TX > queue length to never reduce to 0i, which causes rtl_pci_flush() to be stuck > in > unterminated while-loop. > > This patch removes clear_interrupt() in enable_interrupt() to avoid this > behavior. > > Signed-off-by: Vincent Fann <vincent_f...@realtek.com> > Signed-off-by: Shao Fu <sha...@realtek.com> > Signed-off-by: Larry Finger <larry.fin...@lwfinger.net> > Cc: Stable <sta...@vger.kernel.org> [3.18+] > --- > > Kalle, > > This patch is a little large for the current kernel and stable; however, it > only > deletes code that is clearly wrong. I hope it will be OK.
This isn't a recent regression nor a crasher (or similar) so I can't really justify to send this to 4.1 this late. The way I see it this could easily wait for 4.2, right? -- Kalle Valo -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
