Hello, Since size_t is unsigned, avail will not be less than 0 on line 742. Perhaps just reorganize the computation on line 740. julia ---------- Forwarded message ---------- Date: Tue, 27 Nov 2018 16:13:53 +0800 From: kbuild test robot <lkp@xxxxxxxxx> To: kbuild@xxxxxx Cc: Julia Lawall <julia.lawall@xxxxxxx> Subject: Re: [PATCH] tty: serial: qcom_geni_serial: Fix softlock CC: kbuild-all@xxxxxx In-Reply-To: <20181127022536.104663-1-ryandcase@xxxxxxxxxxxx> References: <20181127022536.104663-1-ryandcase@xxxxxxxxxxxx> TO: Ryan Case <ryandcase@xxxxxxxxxxxx> CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, Jiri Slaby <jslaby@xxxxxxxx>, Evan Green <evgreen@xxxxxxxxxxxx>, Doug Anderson <dianders@xxxxxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx, linux-serial@xxxxxxxxxxxxxxx, Ryan Case <ryandcase@xxxxxxxxxxxx> CC: Evan Green <evgreen@xxxxxxxxxxxx>, Doug Anderson <dianders@xxxxxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx, linux-serial@xxxxxxxxxxxxxxx, Ryan Case <ryandcase@xxxxxxxxxxxx> Hi Ryan, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on tty/tty-testing] [also build test WARNING on v4.20-rc4 next-20181126] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Ryan-Case/tty-serial-qcom_geni_serial-Fix-softlock/20181127-102810 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing :::::: branch date: 6 hours ago :::::: commit date: 6 hours ago >> drivers/tty/serial/qcom_geni_serial.c:742:5-10: WARNING: Unsigned expression compared with zero: avail < 0 # https://github.com/0day-ci/linux/commit/407559b41ed61fd8c95ebe39539677bc577c7c66 git remote add linux-review https://github.com/0day-ci/linux git remote update linux-review git checkout 407559b41ed61fd8c95ebe39539677bc577c7c66 vim +742 drivers/tty/serial/qcom_geni_serial.c c4f528795 Karthikeyan Ramasubramanian 2018-03-14 712 407559b41 Ryan Case 2018-11-26 713 static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done, 407559b41 Ryan Case 2018-11-26 714 bool active) c4f528795 Karthikeyan Ramasubramanian 2018-03-14 715 { c4f528795 Karthikeyan Ramasubramanian 2018-03-14 716 struct qcom_geni_serial_port *port = to_dev_port(uport, uport); c4f528795 Karthikeyan Ramasubramanian 2018-03-14 717 struct circ_buf *xmit = &uport->state->xmit; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 718 size_t avail; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 719 size_t remaining; 407559b41 Ryan Case 2018-11-26 720 size_t pending; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 721 int i; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 722 u32 status; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 723 unsigned int chunk; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 724 int tail; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 725 c4f528795 Karthikeyan Ramasubramanian 2018-03-14 726 status = readl_relaxed(uport->membase + SE_GENI_TX_FIFO_STATUS); 407559b41 Ryan Case 2018-11-26 727 407559b41 Ryan Case 2018-11-26 728 /* Complete the current tx command before taking newly added data */ 407559b41 Ryan Case 2018-11-26 729 if (active) 407559b41 Ryan Case 2018-11-26 730 pending = port->cur_tx_remaining; 407559b41 Ryan Case 2018-11-26 731 else 407559b41 Ryan Case 2018-11-26 732 pending = uart_circ_chars_pending(xmit); 407559b41 Ryan Case 2018-11-26 733 407559b41 Ryan Case 2018-11-26 734 /* All data has been transmitted and acknowledged as received */ 407559b41 Ryan Case 2018-11-26 735 if (!pending && !status && done) { c4f528795 Karthikeyan Ramasubramanian 2018-03-14 736 qcom_geni_serial_stop_tx(uport); c4f528795 Karthikeyan Ramasubramanian 2018-03-14 737 goto out_write_wakeup; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 738 } c4f528795 Karthikeyan Ramasubramanian 2018-03-14 739 407559b41 Ryan Case 2018-11-26 740 avail = port->tx_fifo_depth - (status & TX_FIFO_WC); 407559b41 Ryan Case 2018-11-26 741 avail *= port->tx_bytes_pw; 407559b41 Ryan Case 2018-11-26 @742 if (avail < 0) 407559b41 Ryan Case 2018-11-26 743 avail = 0; 8a8a66a1a Girish Mahadevan 2018-07-13 744 638a6f4eb Evan Green 2018-05-09 745 tail = xmit->tail; 407559b41 Ryan Case 2018-11-26 746 chunk = min3((size_t)pending, (size_t)(UART_XMIT_SIZE - tail), avail); c4f528795 Karthikeyan Ramasubramanian 2018-03-14 747 if (!chunk) c4f528795 Karthikeyan Ramasubramanian 2018-03-14 748 goto out_write_wakeup; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 749 407559b41 Ryan Case 2018-11-26 750 if (!port->cur_tx_remaining) { 407559b41 Ryan Case 2018-11-26 751 qcom_geni_serial_setup_tx(uport, pending); 407559b41 Ryan Case 2018-11-26 752 port->cur_tx_remaining = pending; 407559b41 Ryan Case 2018-11-26 753 } c4f528795 Karthikeyan Ramasubramanian 2018-03-14 754 c4f528795 Karthikeyan Ramasubramanian 2018-03-14 755 remaining = chunk; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 756 for (i = 0; i < chunk; ) { c4f528795 Karthikeyan Ramasubramanian 2018-03-14 757 unsigned int tx_bytes; 69736b57d Karthikeyan Ramasubramanian 2018-05-03 758 u8 buf[sizeof(u32)]; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 759 int c; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 760 69736b57d Karthikeyan Ramasubramanian 2018-05-03 761 memset(buf, 0, ARRAY_SIZE(buf)); 6a10635e9 Karthikeyan Ramasubramanian 2018-05-03 762 tx_bytes = min_t(size_t, remaining, port->tx_bytes_pw); c4f528795 Karthikeyan Ramasubramanian 2018-03-14 763 for (c = 0; c < tx_bytes ; c++) 69736b57d Karthikeyan Ramasubramanian 2018-05-03 764 buf[c] = xmit->buf[tail + c]; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 765 69736b57d Karthikeyan Ramasubramanian 2018-05-03 766 iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1); c4f528795 Karthikeyan Ramasubramanian 2018-03-14 767 c4f528795 Karthikeyan Ramasubramanian 2018-03-14 768 i += tx_bytes; 638a6f4eb Evan Green 2018-05-09 769 tail += tx_bytes; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 770 uport->icount.tx += tx_bytes; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 771 remaining -= tx_bytes; 407559b41 Ryan Case 2018-11-26 772 port->cur_tx_remaining -= tx_bytes; c4f528795 Karthikeyan Ramasubramanian 2018-03-14 773 } 638a6f4eb Evan Green 2018-05-09 774 638a6f4eb Evan Green 2018-05-09 775 xmit->tail = tail & (UART_XMIT_SIZE - 1); c4f528795 Karthikeyan Ramasubramanian 2018-03-14 776 out_write_wakeup: 638a6f4eb Evan Green 2018-05-09 777 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) c4f528795 Karthikeyan Ramasubramanian 2018-03-14 778 uart_write_wakeup(uport); c4f528795 Karthikeyan Ramasubramanian 2018-03-14 779 } c4f528795 Karthikeyan Ramasubramanian 2018-03-14 780 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
