Re: [PATCH v6 10/12] usb: dbc: add handshake between debug target and host

[Julia Lawall]

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
>
> ---
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