• Vincent Fann's avatar
    rtlwifi: Remove the clear interrupt routine from all drivers · 1277fa2a
    Vincent Fann authored
    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: default avatarVincent Fann <vincent_fann@realtek.com>
    Signed-off-by: default avatarShao Fu <shaofu@realtek.com>
    Signed-off-by: default avatarLarry Finger <Larry.Finger@lwfinger.net>
    Cc: Stable <stable@vger.kernel.org> [3.18+]
    Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
    1277fa2a
hw.c 75.6 KB