From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7433 invoked by alias); 5 Feb 2015 19:30:23 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 7400 invoked by uid 48); 5 Feb 2015 19:30:18 -0000 From: "manuel.reimer at gmx dot de" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/64953] New: Compiling sourcecode for STM32F103 causes USB errors with some optimization settings Date: Thu, 05 Feb 2015 19:30:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c X-Bugzilla-Version: 4.9.2 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: manuel.reimer at gmx dot de X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2015-02/txt/msg00501.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64953 Bug ID: 64953 Summary: Compiling sourcecode for STM32F103 causes USB errors with some optimization settings Product: gcc Version: 4.9.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: manuel.reimer at gmx dot de I've tried to compile this sourcecode for an STM32F103 controller: https://github.com/tormodvolden/maple-bootloader/tree/unify_platforms I've modified the Makefile to use "-Os" to reduce size used in flash. This worked well, so far, with an gcc 4.8 compiler. But if I do this with a 4.9.2 compiler, then the USB handshake fails with ugly errors on dmesg: [ 2068.103728] usb 1-1: new full-speed USB device number 2 using xhci_hcd [ 2068.217014] usb 1-1: device descriptor read/64, error -71 [ 2068.323573] xhci_hcd 0000:02:00.0: Setup ERROR: setup context command for slot 1. [ 2068.327349] usb 1-1: hub failed to enable device, error -22 [ 2068.436815] usb 1-1: new full-speed USB device number 3 using xhci_hcd [ 2068.550102] usb 1-1: device descriptor read/64, error 18 [ 2068.656663] xhci_hcd 0000:02:00.0: Setup ERROR: setup context command for slot 1. [ 2068.660448] usb 1-1: hub failed to enable device, error -22 [ 2068.773235] usb 1-1: new full-speed USB device number 4 using xhci_hcd [ 2068.773866] xhci_hcd 0000:02:00.0: ERROR: unexpected setup address command completion code 0x6. [ 2068.980792] xhci_hcd 0000:02:00.0: ERROR: unexpected setup address command completion code 0x6. [ 2069.186265] usb 1-1: device not accepting address 4, error -22 [ 2069.296195] usb 1-1: new full-speed USB device number 5 using xhci_hcd [ 2069.296483] xhci_hcd 0000:02:00.0: ERROR: unexpected setup address command completion code 0x6. [ 2069.503332] xhci_hcd 0000:02:00.0: ERROR: unexpected setup address command completion code 0x6. [ 2069.709220] usb 1-1: device not accepting address 5, error -22 [ 2069.713114] usb usb1-port1: unable to enumerate USB device After some trying I've found out that the key in this case is the optimization setting. If I use "-O3", then the resulting binary works again if I use the 4.9.2 compiler. So "something" is wrong with the optimization. Can someone give me a hint about what changed between 4.8 and 4.9.2? Is this a bug in the gcc compiler or do I just need some new "compiler switch" to disable "some new feature" and get a valid binary, again?