Please check. As far as I can see, the call to early_xdbc_read ends up at xdbc_bulk_transfer, which return negative error codes on failure. julia On Tue, 26 Jan 2016, kbuild test robot wrote: > CC: kbuild-all@xxxxxx > In-Reply-To: <1453781665-4714-11-git-send-email-baolu.lu@xxxxxxxxxxxxxxx> > TO: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > CC: linux-usb@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > > Hi Lu, > > [auto build test WARNING on usb/usb-testing] > [also build test WARNING on v4.5-rc1 next-20160125] > [if your patch is applied to the wrong git tree, please drop us a note to help improving the system] > > url: https://github.com/0day-ci/linux/commits/Lu-Baolu/usb-early-add-support-for-early-printk-through-USB3-debug-port/20160126-122049 > base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > :::::: branch date: 5 hours ago > :::::: commit date: 5 hours ago > > >> drivers/usb/early/xhci-dbc.c:917:6-10: WARNING: Unsigned expression compared with zero: size > 0 > > git remote add linux-review https://github.com/0day-ci/linux > git remote update linux-review > git checkout cdae956781925bbc269faa7f40c931a2825be11a > vim +917 drivers/usb/early/xhci-dbc.c > > 5319db53 Lu Baolu 2016-01-26 901 > 5319db53 Lu Baolu 2016-01-26 902 /* hand over the owner of host from BIOS */ > 5319db53 Lu Baolu 2016-01-26 903 xdbc_bios_handoff(); > 5319db53 Lu Baolu 2016-01-26 904 > 5319db53 Lu Baolu 2016-01-26 905 ret = xdbc_setup(); > 5319db53 Lu Baolu 2016-01-26 906 if (ret < 0) { > 5319db53 Lu Baolu 2016-01-26 907 pr_notice("failed to setup xHCI DbC connection\n"); > 5319db53 Lu Baolu 2016-01-26 908 xdbcp->xhci_base = NULL; > 5319db53 Lu Baolu 2016-01-26 909 xdbcp->xdbc_reg = NULL; > 12cd5775 Lu Baolu 2016-01-26 910 xdbc_dump_debug_buffer(); > 5319db53 Lu Baolu 2016-01-26 911 return ret; > 5319db53 Lu Baolu 2016-01-26 912 } > 5319db53 Lu Baolu 2016-01-26 913 > cdae9567 Lu Baolu 2016-01-26 914 while (retry > 0) { > cdae9567 Lu Baolu 2016-01-26 915 early_xdbc_write(NULL, ping, strlen(ping)); > cdae9567 Lu Baolu 2016-01-26 916 size = early_xdbc_read(NULL, pong, 64); > cdae9567 Lu Baolu 2016-01-26 @917 if (size > 0) { > cdae9567 Lu Baolu 2016-01-26 918 xdbc_trace("%s: pong message: %s\n", __func__, pong); > cdae9567 Lu Baolu 2016-01-26 919 if (pong[0] == 'Y' || pong[0] == 'y') > cdae9567 Lu Baolu 2016-01-26 920 break; > cdae9567 Lu Baolu 2016-01-26 921 } else { > cdae9567 Lu Baolu 2016-01-26 922 xdbc_trace("%s: pong message error %d\n", > cdae9567 Lu Baolu 2016-01-26 923 __func__, size); > cdae9567 Lu Baolu 2016-01-26 924 } > cdae9567 Lu Baolu 2016-01-26 925 > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html