On Wed, 2012-11-28 at 09:21 +0000, David Laight wrote: > Even when it might make sense to sleep in close until tx drains > there needs to be a finite timeout before it become abortive.
You are, of course, right. We should never wait for hardware for ever.
And just to serve me right, I seem to have hit a bug in the latest Solos
firmware (1.11) which makes it sometimes lock up when I reboot. So it
never responds to the PKT_PCLOSE packet... and thus it deadlocks when I
try to kill pppd and unload the module to reset it :)
New version...
From 53dd01c08fec5b26006a009b25e4210127fdb27a Mon Sep 17 00:00:00 2001
From: David Woodhouse <david.woodho...@intel.com>
Date: Tue, 27 Nov 2012 23:49:24 +0000
Subject: [PATCH] solos-pci: Wait for pending TX to complete when releasing
vcc
We should no longer be calling the old pop routine for the vcc, after
vcc_release() has completed. Make sure we wait for any pending TX skbs
to complete, by waiting for our own PKT_PCLOSE control skb to be sent.
Signed-off-by: David Woodhouse <david.woodho...@intel.com>
---
drivers/atm/solos-pci.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index 9851093..3720670 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -92,6 +92,7 @@ struct pkt_hdr {
};
struct solos_skb_cb {
+ struct completion c;
struct atm_vcc *vcc;
uint32_t dma_addr;
};
@@ -881,11 +882,18 @@ static void pclose(struct atm_vcc *vcc)
header->vci = cpu_to_le16(vcc->vci);
header->type = cpu_to_le16(PKT_PCLOSE);
+ init_completion(&SKB_CB(skb)->c);
+
fpga_queue(card, SOLOS_CHAN(vcc->dev), skb, NULL);
clear_bit(ATM_VF_ADDR, &vcc->flags);
clear_bit(ATM_VF_READY, &vcc->flags);
+ if (!wait_for_completion_timeout(&SKB_CB(skb)->c,
+ jiffies + msecs_to_jiffies(5000)))
+ dev_warn(&card->dev->dev, "Timeout waiting for VCC close on
port %d\n",
+ SOLOS_CHAN(vcc->dev));
+
/* Hold up vcc_destroy_socket() (our caller) until solos_bh() in the
tasklet has finished processing any incoming packets (and, more to
the point, using the vcc pointer). */
@@ -1011,9 +1019,12 @@ static uint32_t fpga_tx(struct solos_card *card)
if (vcc) {
atomic_inc(&vcc->stats->tx);
solos_pop(vcc, oldskb);
- } else
+ } else {
+ struct pkt_hdr *header = (void *)oldskb->data;
+ if (le16_to_cpu(header->type) == PKT_PCLOSE)
+ complete(&SKB_CB(oldskb)->c);
dev_kfree_skb_irq(oldskb);
-
+ }
}
}
/* For non-DMA TX, write the 'TX start' bit for all four ports
simultaneously */
@@ -1345,6 +1356,8 @@ static struct pci_driver fpga_driver = {
static int __init solos_pci_init(void)
{
+ BUILD_BUG_ON(sizeof(struct solos_skb_cb) > sizeof(((struct sk_buff
*)0)->cb));
+
printk(KERN_INFO "Solos PCI Driver Version %s\n", VERSION);
return pci_register_driver(&fpga_driver);
}
--
1.8.0
--
dwmw2
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