[S] Change in osmo-e1-hardware[master]: icE1usb fw: Workaround some apparent GCC aliasing bug ...

tnt has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-e1-hardware/+/36175?usp=email ) Change subject: icE1usb fw: Workaround some apparent GCC aliasing bug ... ...................................................................... icE1usb fw: Workaround some apparent GCC aliasing bug ... If the code is built either : * without -flto * with -fno-strict-aliasing * with that struct as 'static' (so it's not on the stack) Then all works fine. But in the current situation (without the patch), GCC seems to think there is some aliasing and just plain removed the `notif.bits = 1` bit of code in that functions (no warnings printed ...). Putting the struct as 'static' is the least awful workaround. I didn't bother reporting bug upstream, because I can't reproduce on a small test case and I'm sure I'd just get yelled at and that the compiler is right for some reason ... Signed-off-by: Sylvain Munaut <tnt(a)246tNt.com> Change-Id: Ie0a2ce337ce4a9c08c3d27acc4d922a3e5892840 --- M firmware/ice40-riscv/icE1usb/usb_gps.c 1 file changed, 28 insertions(+), 1 deletion(-) git pull ssh://gerrit.osmocom.org:29418/osmo-e1-hardware refs/changes/75/36175/1 diff --git a/firmware/ice40-riscv/icE1usb/usb_gps.c b/firmware/ice40-riscv/icE1usb/usb_gps.c index f2b09b4..e219cf8 100644 --- a/firmware/ice40-riscv/icE1usb/usb_gps.c +++ b/firmware/ice40-riscv/icE1usb/usb_gps.c @@ -143,7 +143,8 @@ if ((ep_regs->bd[0].csr & USB_BD_STATE_MSK) != USB_BD_STATE_RDY_DATA) { /* Default request */ - struct usb_cdc_notif_serial_state notif = { + /* Put as static to work around gcc aliasing bug ... */ + static struct usb_cdc_notif_serial_state notif = { .hdr = { .bmRequestType = USB_REQ_READ | USB_REQ_TYPE_CLASS | USB_REQ_RCPT_INTF, .bRequest = USB_NOTIF_CDC_SERIAL_STATE, -- To view, visit https://gerrit.osmocom.org/c/osmo-e1-hardware/+/36175?usp=email To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: osmo-e1-hardware Gerrit-Branch: master Gerrit-Change-Id: Ie0a2ce337ce4a9c08c3d27acc4d922a3e5892840 Gerrit-Change-Number: 36175 Gerrit-PatchSet: 1 Gerrit-Owner: tnt <tnt(a)246tNt.com> Gerrit-MessageType: newchange