On Tue, 14 Sep 2010 12:17:21 -0700 Andrew Morton <a...@linux-foundation.org> wrote:
> On Fri, 20 Aug 2010 13:45:21 -0500 > Timur Tabi <ti...@freescale.com> wrote: > > > hvc_console_print() calls the HVC client driver's put_chars() callback > > to write some characters to the console. If the callback returns 0, that > > indicates that no characters were written (perhaps the output buffer is > > full), but hvc_console_print() treats that as an error and discards the > > rest of the buffer. > > > > So change hvc_console_print() to just loop and call put_chars() again if it > > returns a 0 return code. > > Seems rather dangerous. The upper layer will sit there chewing 100% > CPU for as long as the lower layer is congested. This is just for printk(), not user output. This is exactly what printk() has always done for real serial ports. > > This change makes hvc_console_print() behave more like hvc_push(), which > > does check for a 0 return code and re-schedules itself. > > Yes, hvc_push() reschedules. hvc_push() is not relevant to kernel console output. hvc_console_write() currently does not reschedule anything. It just drops characters when busy. -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
