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authorSuleiman Souhlal <suleiman@google.com>2007-04-10 16:38:37 -0400
committerBartlomiej Zolnierkiewicz <bzolnier@gmail.com>2007-04-10 16:38:37 -0400
commit23450319e2890986c247ec0aa1442f060e657e6d (patch)
treec30fc173d8b97343f8ae7b1b1ed511366af256ab /include/linux
parent90f30eccf41302a2542f5d374af243061902bd98 (diff)
ide: correctly prevent IDE timer expiry function to run if request was already handled
It is possible for the timer expiry function to run even though the request has already been handled: ide_timer_expiry() only checks that the handler is not NULL, but it is possible that we have handled a request (thus clearing the handler) and then started a new request (thus starting the timer again, and setting a handler). A simple way to exhibit this is to set the DMA timeout to 1 jiffy and run dd: The kernel will panic after a few minutes because ide_timer_expiry() tries to add a timer when it's already active. To fix this, we simply add a request generation count that gets incremented at every interrupt, and check in ide_timer_expiry() that we have not already handled a new interrupt before running the expiry function. Signed-off-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/ide.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 58564a199862..d3bbc7188b6a 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -861,6 +861,8 @@ typedef struct hwgroup_s {
861 int (*expiry)(ide_drive_t *); 861 int (*expiry)(ide_drive_t *);
862 /* ide_system_bus_speed */ 862 /* ide_system_bus_speed */
863 int pio_clock; 863 int pio_clock;
864 int req_gen;
865 int req_gen_timer;
864 866
865 unsigned char cmd_buf[4]; 867 unsigned char cmd_buf[4];
866} ide_hwgroup_t; 868} ide_hwgroup_t;