On Wed, Apr 25, 2018 at 1:20 PM, Andrew Jones <drjones@xxxxxxxxxx> wrote: > On Mon, Apr 23, 2018 at 02:49:30PM +0100, Peter Maydell wrote: >> On 23 April 2018 at 14:41, Dave Martin <Dave.Martin@xxxxxxx> wrote: >> > This is an update to a previous RFC v2 [1], to fix a problem observed by >> > the qemu community that causes serial input to hang when booting a >> > simulated system with data already queued in the UART FIFO [2]. >> > >> > After discussion, I decided that the approach in [1] was over- >> > engineered: it tries to preserve a guarantee that people shouldn't be >> > relying on anyway, namely that data sent to the UART prior to kernel >> > boot will be received by the kernel; or more generally that data >> > received by the UART while the pl011 driver is not opened will be >> > received (either intact or at all) by the driver. >> > >> > If anyone can please test the following and let me know the results, >> > that would be much appreciated! >> > >> > a) Check that you can still reproduce the bug on mainline without this >> > patch. >> > >> > b) Check whether this patch fixes the problem. >> >> Thanks. I'm cc'ing Ciro and Drew, who are the two people I >> recall reporting this issue to me. >> Link to the patch for their benefit: >> http://lists.infradead.org/pipermail/linux-arm-kernel/2018-April/573120.html >> > > Hi Dave, > > v3 does not resolve the issue for me. v2 does, and, fwiw, v3 applied on > top of v2 (i.e. applying both), still works. > I also confirm that v2 + v3 on top of Linux kernel v4.16, QEMU v2.11.0 solves the problem on arm and aarch64, otherwise if I hit Ctrl + C during boot my terminal become irresponsive after boot. Test setup: https://github.com/cirosantilli/linux-kernel-module-cheat/tree/14965a40d27c8d9d1ff5b023ace827b288a024ef > If you choose to go with v2, then you can add my tested-by. > > Thanks, > drew -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
