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[04/27] fdc: handle read-only floppies (abort early on write commands)

Message ID 1330528688-21996-5-git-send-email-kwolf@redhat.com
State New
Headers show

Commit Message

Kevin Wolf Feb. 29, 2012, 3:17 p.m. UTC 
From: Hervé Poussineau <hpoussin@reactos.org>

A real floppy doesn't attempt to write to read-only media either.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/fdc.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
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Patch

diff --git a/hw/fdc.c b/hw/fdc.c
index 9d1f5b3..3d4bb11 100644
--- a/hw/fdc.c
+++ b/hw/fdc.c
@@ -300,6 +300,7 @@  enum {
 };
 
 enum {
+    FD_SR1_NW       = 0x02, /* Not writable */
     FD_SR1_EC       = 0x80, /* End of cylinder */
 };
 
@@ -1179,6 +1180,16 @@  static int fdctrl_transfer_handler (void *opaque, int nchan,
             break;
         case FD_DIR_WRITE:
             /* WRITE commands */
+            if (cur_drv->ro) {
+                /* Handle readonly medium early, no need to do DMA, touch the
+                 * LED or attempt any writes. A real floppy doesn't attempt
+                 * to write to readonly media either. */
+                fdctrl_stop_transfer(fdctrl,
+                                     FD_SR0_ABNTERM | FD_SR0_SEEK, FD_SR1_NW,
+                                     0x00);
+                goto transfer_error;
+            }
+
             DMA_read_memory (nchan, fdctrl->fifo + rel_pos,
                              fdctrl->data_pos, len);
             if (bdrv_write(cur_drv->bs, fd_sector(cur_drv),