| Message ID | 1455561693-28615-1-git-send-email-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 15 Feb 2016, Jean-Philippe Brucker wrote: > Since commit 27a4c827c34ac4256a190cc9d24607f953c1c459 > fbcon: use the cursor blink interval provided by vt > > two attempts have been made at fixing a possible hang caused by > cursor_timer_handler. That function registers a timer to be triggered at > "jiffies + fbcon_ops.cur_blink_jiffies". ... > Instead of patching all possible paths that lead to this case one at a > time, fix the issue at the source and initialise cur_blink_jiffies to > 200ms when allocating fbcon_ops. This was its default value before > aforesaid commit. fbcon_cursor or fbcon_init will refine this value > downstream. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > Cc: <stable@vger.kernel.org> # v4.2 I agree with the approach and the patch works on my x86_64. Tested-by: Scot Doyle <lkml14@scotdoyle.com> -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 15/02/16 20:41, Jean-Philippe Brucker wrote: > Since commit 27a4c827c34ac4256a190cc9d24607f953c1c459 > fbcon: use the cursor blink interval provided by vt > > two attempts have been made at fixing a possible hang caused by > cursor_timer_handler. That function registers a timer to be triggered at > "jiffies + fbcon_ops.cur_blink_jiffies". > > A new case had been encountered during initialisation of clcd-pl11x: > > fbcon_fb_registered > do_fbcon_takeover > > -> do_register_con_driver > fbcon_startup > (A) add_cursor_timer (with cur_blink_jiffies = 0) > > -> do_bind_con_driver > visual_init > fbcon_init > (B) cur_blink_jiffies = msecs_to_jiffies(vc->vc_cur_blink_ms); > > If we take an softirq anywhere between A and B (and we do), > cursor_timer_handler executes indefinitely. > > Instead of patching all possible paths that lead to this case one at a > time, fix the issue at the source and initialise cur_blink_jiffies to > 200ms when allocating fbcon_ops. This was its default value before > aforesaid commit. fbcon_cursor or fbcon_init will refine this value > downstream. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > Cc: <stable@vger.kernel.org> # v4.2 > --- > drivers/video/console/fbcon.c | 2 ++ > 1 file changed, 2 insertions(+) Thanks, queued for 4.5 fixes. Tomi
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index 92f3949..6e92917 100644 --- a/drivers/video/console/fbcon.c +++ b/drivers/video/console/fbcon.c @@ -709,6 +709,7 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, } if (!err) { + ops->cur_blink_jiffies = HZ / 5; info->fbcon_par = ops; if (vc) @@ -956,6 +957,7 @@ static const char *fbcon_startup(void) ops->currcon = -1; ops->graphics = 1; ops->cur_rotate = -1; + ops->cur_blink_jiffies = HZ / 5; info->fbcon_par = ops; p->con_rotate = initial_rotation; set_blitting_type(vc, info);
Since commit 27a4c827c34ac4256a190cc9d24607f953c1c459 fbcon: use the cursor blink interval provided by vt two attempts have been made at fixing a possible hang caused by cursor_timer_handler. That function registers a timer to be triggered at "jiffies + fbcon_ops.cur_blink_jiffies". A new case had been encountered during initialisation of clcd-pl11x: fbcon_fb_registered do_fbcon_takeover -> do_register_con_driver fbcon_startup (A) add_cursor_timer (with cur_blink_jiffies = 0) -> do_bind_con_driver visual_init fbcon_init (B) cur_blink_jiffies = msecs_to_jiffies(vc->vc_cur_blink_ms); If we take an softirq anywhere between A and B (and we do), cursor_timer_handler executes indefinitely. Instead of patching all possible paths that lead to this case one at a time, fix the issue at the source and initialise cur_blink_jiffies to 200ms when allocating fbcon_ops. This was its default value before aforesaid commit. fbcon_cursor or fbcon_init will refine this value downstream. Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Cc: <stable@vger.kernel.org> # v4.2 --- drivers/video/console/fbcon.c | 2 ++ 1 file changed, 2 insertions(+)