From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54881) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WPybN-0005yV-4e for qemu-devel@nongnu.org; Tue, 18 Mar 2014 14:19:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WPybG-0006yb-KO for qemu-devel@nongnu.org; Tue, 18 Mar 2014 14:19:01 -0400 Received: from mail-oa0-x22e.google.com ([2607:f8b0:4003:c02::22e]:59601) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WPybG-0006yV-F4 for qemu-devel@nongnu.org; Tue, 18 Mar 2014 14:18:54 -0400 Received: by mail-oa0-f46.google.com with SMTP id i7so7410033oag.19 for ; Tue, 18 Mar 2014 11:18:54 -0700 (PDT) From: Rob Herring Date: Tue, 18 Mar 2014 13:18:40 -0500 Message-Id: <1395166721-15716-3-git-send-email-robherring2@gmail.com> In-Reply-To: <1395166721-15716-1-git-send-email-robherring2@gmail.com> References: <1395166721-15716-1-git-send-email-robherring2@gmail.com> Subject: [Qemu-devel] [PATCH v3 2/3] pl011: fix UARTRSR accesses corrupting the UARTCR value List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, Peter Maydell Cc: Rob Herring From: Rob Herring Offset 4 is UARTRSR/UARTECR, not the UARTCR. The UARTCR would be corrupted if the UARTRSR is ever written. Fix by implementing a correct model of the UARTRSR/UARTECR register. Reads of this register simply reflect the error bits in data register. Only breaks can be triggered in QEMU. With the pl011_can_receive function, we effectively have flow control between the host and the model. Framing and parity errors simply don't make sense in the model and will never occur. Signed-off-by: Rob Herring --- hw/char/pl011.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/hw/char/pl011.c b/hw/char/pl011.c index 8103e2e..11c3a75 100644 --- a/hw/char/pl011.c +++ b/hw/char/pl011.c @@ -20,6 +20,7 @@ typedef struct PL011State { uint32_t readbuff; uint32_t flags; uint32_t lcr; + uint32_t rsr; uint32_t cr; uint32_t dmacr; uint32_t int_enabled; @@ -81,13 +82,14 @@ static uint64_t pl011_read(void *opaque, hwaddr offset, } if (s->read_count == s->read_trigger - 1) s->int_level &= ~ PL011_INT_RX; + s->rsr = c >> 8; pl011_update(s); if (s->chr) { qemu_chr_accept_input(s->chr); } return c; - case 1: /* UARTCR */ - return 0; + case 1: /* UARTRSR */ + return s->rsr; case 6: /* UARTFR */ return s->flags; case 8: /* UARTILPR */ @@ -146,8 +148,8 @@ static void pl011_write(void *opaque, hwaddr offset, s->int_level |= PL011_INT_TX; pl011_update(s); break; - case 1: /* UARTCR */ - s->cr = value; + case 1: /* UARTRSR/UARTECR */ + s->rsr = 0; break; case 6: /* UARTFR */ /* Writes to Flag register are ignored. */ @@ -247,13 +249,14 @@ static const MemoryRegionOps pl011_ops = { static const VMStateDescription vmstate_pl011 = { .name = "pl011", - .version_id = 1, - .minimum_version_id = 1, - .minimum_version_id_old = 1, + .version_id = 2, + .minimum_version_id = 2, + .minimum_version_id_old = 2, .fields = (VMStateField[]) { VMSTATE_UINT32(readbuff, PL011State), VMSTATE_UINT32(flags, PL011State), VMSTATE_UINT32(lcr, PL011State), + VMSTATE_UINT32(rsr, PL011State), VMSTATE_UINT32(cr, PL011State), VMSTATE_UINT32(dmacr, PL011State), VMSTATE_UINT32(int_enabled, PL011State), -- 1.8.3.2