[linux-dvb] RFC - Flexcop Streaming watchdog (VDSB)
Patrick Boettcher
patrick.boettcher at desy.de
Fri Jan 16 16:03:10 CET 2009
Hi lists,
For years there has been the Video Data Stream Borken-error with VDR and
Technisat cards: The error occured randomly and unfrequently. A
work-around for that problem was to restart VDR and let the driver reset
the pid-filtering and streaming interface.
In fact it turned out, that the problem is worse with setups not based on
VDR and the "VDSB-error" could be really easily reproduced (I'm not sure
if this applies to all generations on SkyStar2-card). I'm skipping the
description of the problem here...
Attached you'll find a patch which works around the hardware bug which is
causing VDSB-error without needing to reload the driver.
There a struct-work-watchdog looking at the number of irq-received while
having PIDs active in the PID-filter. If no IRQs are received, the
pid-filter-system is reset.
It seems to fix the problem and so far I've not seen any false positives
(like resetting the pid-filter even though streaming is working fine).
Before asking to pull the patch I'd like to discuss an issue: my
work-around is iterating over the pid-filter-list in the dvb_demux. I'm
doing this in the struct-work-callback. In dvb_demux.c I see that this
list is protected with a spinlock. When I now try to take the spinlock in
the work-function I'll get a nice message saying, that I cannot do take a
spinlock in a work-function.
What can I do? What is the proper way to protect access to this list? Is
it needed at all?
thanks for you input in advance,
Patrick.
--
Mail: patrick.boettcher at desy.de
WWW: http://www.wi-bw.tfh-wildau.de/~pboettch/
-------------- next part --------------
diff -r 7981bdd4e25a linux/drivers/media/dvb/b2c2/flexcop-hw-filter.c
--- a/linux/drivers/media/dvb/b2c2/flexcop-hw-filter.c Mon Jan 12 00:18:04 2009 +0000
+++ b/linux/drivers/media/dvb/b2c2/flexcop-hw-filter.c Fri Jan 16 15:46:32 2009 +0100
@@ -179,7 +179,7 @@
/* if it was the first or last feed request change the stream-status */
if (fc->feedcount == onoff) {
- flexcop_rcv_data_ctrl(fc,onoff);
+ flexcop_rcv_data_ctrl(fc, onoff);
if (fc->stream_control) /* device specific stream control */
fc->stream_control(fc,onoff);
@@ -192,6 +192,7 @@
return 0;
}
+EXPORT_SYMBOL(flexcop_pid_feed_control);
void flexcop_hw_filter_init(struct flexcop_device *fc)
{
diff -r 7981bdd4e25a linux/drivers/media/dvb/b2c2/flexcop-pci.c
--- a/linux/drivers/media/dvb/b2c2/flexcop-pci.c Mon Jan 12 00:18:04 2009 +0000
+++ b/linux/drivers/media/dvb/b2c2/flexcop-pci.c Fri Jan 16 15:46:32 2009 +0100
@@ -13,9 +13,9 @@
module_param(enable_pid_filtering, int, 0444);
MODULE_PARM_DESC(enable_pid_filtering, "enable hardware pid filtering: supported values: 0 (fullts), 1");
-static int irq_chk_intv;
+static int irq_chk_intv = 100;
module_param(irq_chk_intv, int, 0644);
-MODULE_PARM_DESC(irq_chk_intv, "set the interval for IRQ watchdog (currently just debugging).");
+MODULE_PARM_DESC(irq_chk_intv, "set the interval for IRQ streaming watchdog.");
#ifdef CONFIG_DVB_B2C2_FLEXCOP_DEBUG
#define dprintk(level,args...) \
@@ -34,7 +34,7 @@
static int debug;
module_param(debug, int, 0644);
-MODULE_PARM_DESC(debug, "set debug level (1=info,2=regs,4=TS,8=irqdma (|-able))." DEBSTATUS);
+MODULE_PARM_DESC(debug, "set debug level (1=info,2=regs,4=TS,8=irqdma,16=check (|-able))." DEBSTATUS);
#define DRIVER_VERSION "0.1"
#define DRIVER_NAME "Technisat/B2C2 FlexCop II/IIb/III Digital TV PCI Driver"
@@ -58,6 +58,8 @@
int active_dma1_addr; /* 0 = addr0 of dma1; 1 = addr1 of dma1 */
u32 last_dma1_cur_pos; /* position of the pointer last time the timer/packet irq occured */
int count;
+ int count_prev;
+ int stream_problem;
spinlock_t irq_lock;
@@ -115,18 +117,47 @@
#endif
struct flexcop_device *fc = fc_pci->fc_dev;
- flexcop_ibi_value v = fc->read_ibi_reg(fc,sram_dest_reg_714);
+ if (fc->feedcount) {
+ flexcop_ibi_value v = fc->read_ibi_reg(fc,sram_dest_reg_714);
- flexcop_dump_reg(fc_pci->fc_dev,dma1_000,4);
+ // flexcop_dump_reg(fc_pci->fc_dev,dma1_000,4);
- if (v.sram_dest_reg_714.net_ovflow_error)
- deb_chk("sram net_ovflow_error\n");
- if (v.sram_dest_reg_714.media_ovflow_error)
- deb_chk("sram media_ovflow_error\n");
- if (v.sram_dest_reg_714.cai_ovflow_error)
- deb_chk("sram cai_ovflow_error\n");
- if (v.sram_dest_reg_714.cai_ovflow_error)
- deb_chk("sram cai_ovflow_error\n");
+#if 0
+ deb_chk("net_ovflow_error: %d, media_ovflow_error: %d, cai_ovflow_error: %d, cao_ovflow_error: %d, sram_dma: %d, maximumfill: %d\n",
+ v.sram_dest_reg_714.net_ovflow_error,
+ v.sram_dest_reg_714.media_ovflow_error,
+ v.sram_dest_reg_714.cai_ovflow_error,
+ v.sram_dest_reg_714.cao_ovflow_error,
+ v.sram_dest_reg_714.ctrl_sramdma,
+ v.sram_dest_reg_714.ctrl_maximumfill);
+#endif
+
+ if (fc_pci->count == fc_pci->count_prev) {
+ deb_chk("no IRQ since the last time\n");
+ if (fc_pci->stream_problem++ == 3) {
+ struct dvb_demux_feed *feed;
+ int t = 0;
+
+ /* work-queue is atomic -> cannot
+ * take the demux.lock here, but is it needed? XXX
+ * spin_lock_irq(&fc->demux.lock); */
+ list_for_each_entry(feed, &fc->demux.feed_list, list_head) {
+ flexcop_pid_feed_control(fc, feed, 0);
+ t++;
+ }
+
+ list_for_each_entry(feed, &fc->demux.feed_list, list_head) {
+ flexcop_pid_feed_control(fc, feed, 1);
+ }
+ /* spin_unlock_irq(&fc->demux.lock); */
+
+ fc_pci->stream_problem = 0;
+ }
+ } else {
+ fc_pci->stream_problem = 0;
+ fc_pci->count_prev = fc_pci->count;
+ }
+ }
schedule_delayed_work(&fc_pci->irq_check_work,
msecs_to_jiffies(irq_chk_intv < 100 ? 100 : irq_chk_intv));
@@ -232,16 +263,12 @@
flexcop_dma_control_timer_irq(fc,FC_DMA_1,1);
deb_irq("IRQ enabled\n");
+ fc_pci->count_prev = fc_pci->count;
+
// fc_pci->active_dma1_addr = 0;
// flexcop_dma_control_size_irq(fc,FC_DMA_1,1);
- if (irq_chk_intv > 0)
- schedule_delayed_work(&fc_pci->irq_check_work,
- msecs_to_jiffies(irq_chk_intv < 100 ? 100 : irq_chk_intv));
} else {
- if (irq_chk_intv > 0)
- cancel_delayed_work(&fc_pci->irq_check_work);
-
flexcop_dma_control_timer_irq(fc,FC_DMA_1,0);
deb_irq("IRQ disabled\n");
@@ -315,8 +342,6 @@
IRQF_SHARED, DRIVER_NAME, fc_pci)) != 0)
goto err_pci_iounmap;
-
-
fc_pci->init_state |= FC_PCI_INIT;
return ret;
@@ -395,6 +420,10 @@
INIT_DELAYED_WORK(&fc_pci->irq_check_work, flexcop_pci_irq_check_work);
#endif
+ if (irq_chk_intv > 0)
+ schedule_delayed_work(&fc_pci->irq_check_work,
+ msecs_to_jiffies(irq_chk_intv < 100 ? 100 : irq_chk_intv));
+
return ret;
err_fc_exit:
@@ -412,6 +441,9 @@
static void flexcop_pci_remove(struct pci_dev *pdev)
{
struct flexcop_pci *fc_pci = pci_get_drvdata(pdev);
+
+ if (irq_chk_intv > 0)
+ cancel_delayed_work(&fc_pci->irq_check_work);
flexcop_pci_dma_exit(fc_pci);
flexcop_device_exit(fc_pci->fc_dev);
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