Messages in this thread | | | Date | Wed, 9 Nov 2016 10:37:11 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH v4 1/4] usb: dbc: early driver for xhci debug capability |
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On Tue, 1 Nov 2016, Lu Baolu wrote: > +static void early_xdbc_write(struct console *con, const char *str, u32 n) > +{ > + int chunk, ret; > + static char buf[XDBC_MAX_PACKET]; > + int use_cr = 0; > + > + if (!xdbc.xdbc_reg) > + return; > + memset(buf, 0, XDBC_MAX_PACKET);
How is that dealing with reentrancy?
early_printk() does not protect against it. Peter has a patch to prevent concurrent access from different cpus, but it cannot and will never prevent reentrancy on the same cpu (interrupt, nmi).
Thanks,
tglx
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