Attached is the reworked patch to take care of Andrew's suggestions -

1) Allocate the work struct dynamically in struct ti_ohci during device probe, free it during device remove
2) In ohci1394_pci_remove, ensure queued work, if any, is flushed before the device is removed (As I understand, this should work for both device removal cases as well as module removal - correct?)
3) Rework the free_dma_rcv_ctx - It is called in multiple contexts by different callers - teach it to free the dma according to caller's wish - either direct free where caller determines the context is safe to sleep OR delayed via schedule_work when caller wants to call it from a context where it cannot sleep. So it now takes 2 extra arguments - method to free - direct or delayed and if it is to be freed delayed, an appropriate work_struct.


Andrew - flush_scheduled_work does not touch work which isn't shceduled - so I don't think INIT_WORK in setup is necessary. Let me know if I am missing something here. (I tried INIT_WORK in ochi1394_pci_probe and putting flush_scheduled_work in ohci1394_pci_remove - It did not result in calling the work function after I did rmmod, since it wasn't scheduled.)

Parag


--- drivers/ieee1394/ohci1394.c.orig    2004-12-24 16:35:25.000000000 -0500
+++ drivers/ieee1394/ohci1394.c 2005-01-30 20:00:42.000000000 -0500
@@ -99,6 +99,7 @@
 #include <asm/uaccess.h>
 #include <linux/delay.h>
 #include <linux/spinlock.h>
+#include <linux/workqueue.h>
 
 #include <asm/pgtable.h>
 #include <asm/page.h>
@@ -161,6 +162,10 @@
 #define PRINT(level, fmt, args...) \
 printk(level "%s: fw-host%d: " fmt "\n" , OHCI1394_DRIVER_NAME, ohci->host->id 
, ## args)
 
+/* Instruct free_dma_rcv_ctx how to free dma pools */
+#define OHCI_FREE_DMA_CTX_DIRECT 0
+#define OHCI_FREE_DMA_CTX_DELAYED 1
+
 static char version[] __devinitdata =
        "$Rev: 1223 $ Ben Collins <[EMAIL PROTECTED]>";
 
@@ -176,7 +181,8 @@
                             enum context_type type, int ctx, int num_desc,
                             int buf_size, int split_buf_size, int 
context_base);
 static void stop_dma_rcv_ctx(struct dma_rcv_ctx *d);
-static void free_dma_rcv_ctx(struct dma_rcv_ctx *d);
+static void free_dma_rcv_ctx(struct dma_rcv_ctx *d , int method,
+                            struct work_struct* work);
 
 static int alloc_dma_trm_ctx(struct ti_ohci *ohci, struct dma_trm_ctx *d,
                             enum context_type type, int ctx, int num_desc,
@@ -184,6 +190,8 @@
 
 static void ohci1394_pci_remove(struct pci_dev *pdev);
 
+static void ohci_free_irlc_pci_pool(void* data);
+
 #ifndef __LITTLE_ENDIAN
 static unsigned hdr_sizes[] =
 {
@@ -1117,7 +1125,8 @@
 
                if (ohci->ir_legacy_channels == 0) {
                        stop_dma_rcv_ctx(&ohci->ir_legacy_context);
-                       free_dma_rcv_ctx(&ohci->ir_legacy_context);
+                       INIT_WORK(ohci->irlc_free_dma, ohci_free_irlc_pci_pool, 
ohci->ir_legacy_context.prg_pool);
+                       free_dma_rcv_ctx(&ohci->ir_legacy_context, 
OHCI_FREE_DMA_CTX_DELAYED, ohci->irlc_free_dma);
                        DBGMSG("ISO receive legacy context deactivated");
                }
                 break;
@@ -2876,7 +2885,8 @@
 }
 
 
-static void free_dma_rcv_ctx(struct dma_rcv_ctx *d)
+static void free_dma_rcv_ctx(struct dma_rcv_ctx *d, int method,
+               struct work_struct* work)
 {
        int i;
        struct ti_ohci *ohci = d->ohci;
@@ -2903,8 +2913,20 @@
                                pci_pool_free(d->prg_pool, d->prg_cpu[i], 
d->prg_bus[i]);
                                OHCI_DMA_FREE("consistent dma_rcv prg[%d]", i);
                        }
-               pci_pool_destroy(d->prg_pool);
-               OHCI_DMA_FREE("dma_rcv prg pool");
+               if(method == OHCI_FREE_DMA_CTX_DIRECT)
+               {
+                       pci_pool_destroy(d->prg_pool);
+                       OHCI_DMA_FREE("dma_rcv prg pool");
+               }
+               
+               else if(method == OHCI_FREE_DMA_CTX_DELAYED)
+               {
+                       schedule_work(work);
+               }
+
+               else
+                       PRINT(KERN_ERR, "Invalid method passed - %d", method);
+
                kfree(d->prg_cpu);
                kfree(d->prg_bus);
        }
@@ -2938,7 +2960,7 @@
 
        if (d->buf_cpu == NULL || d->buf_bus == NULL) {
                PRINT(KERN_ERR, "Failed to allocate dma buffer");
-               free_dma_rcv_ctx(d);
+               free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
                return -ENOMEM;
        }
        memset(d->buf_cpu, 0, d->num_desc * sizeof(quadlet_t*));
@@ -2950,7 +2972,7 @@
 
        if (d->prg_cpu == NULL || d->prg_bus == NULL) {
                PRINT(KERN_ERR, "Failed to allocate dma prg");
-               free_dma_rcv_ctx(d);
+               free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
                return -ENOMEM;
        }
        memset(d->prg_cpu, 0, d->num_desc * sizeof(struct dma_cmd*));
@@ -2960,7 +2982,7 @@
 
        if (d->spb == NULL) {
                PRINT(KERN_ERR, "Failed to allocate split buffer");
-               free_dma_rcv_ctx(d);
+               free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
                return -ENOMEM;
        }
 
@@ -2979,7 +3001,7 @@
                } else {
                        PRINT(KERN_ERR,
                              "Failed to allocate dma buffer");
-                       free_dma_rcv_ctx(d);
+                       free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
                        return -ENOMEM;
                }
 
@@ -2991,7 +3013,7 @@
                } else {
                        PRINT(KERN_ERR,
                              "Failed to allocate dma prg");
-                       free_dma_rcv_ctx(d);
+                       free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
                        return -ENOMEM;
                }
        }
@@ -3005,7 +3027,7 @@
                if (ohci1394_register_iso_tasklet(ohci,
                                                  &ohci->ir_legacy_tasklet) < 
0) {
                        PRINT(KERN_ERR, "No IR DMA context available");
-                       free_dma_rcv_ctx(d);
+                       free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
                        return -EBUSY;
                }
 
@@ -3355,6 +3377,7 @@
 
        /* the IR DMA context is allocated on-demand; mark it inactive */
        ohci->ir_legacy_context.ohci = NULL;
+       ohci->ir_legacy_context.prg_pool = NULL;
 
        /* same for the IT DMA context */
        ohci->it_legacy_context.ohci = NULL;
@@ -3377,16 +3400,32 @@
        if (hpsb_add_host(host))
                FAIL(-ENOMEM, "Failed to register host with highlevel");
 
+       ohci->irlc_free_dma = kmalloc(sizeof(struct work_struct), GFP_KERNEL);
+       if(ohci->irlc_free_dma == NULL)
+               FAIL(-ENOMEM, "Failed to allocate memory for 
ohci->irlc_free_dma");
+
        ohci->init_state = OHCI_INIT_DONE;
 
        return 0;
 #undef FAIL
 }
 
+static void ohci_free_irlc_pci_pool(void *data)
+{
+       if(data == NULL)
+               return;
+       pci_pool_destroy(data);
+       OHCI_DMA_FREE("dma_rcv prg pool");
+       return;
+}
+       
 static void ohci1394_pci_remove(struct pci_dev *pdev)
 {
        struct ti_ohci *ohci;
        struct device *dev;
+       
+       /* Ensure all dma ctx are freed */
+       flush_scheduled_work();
 
        ohci = pci_get_drvdata(pdev);
        if (!ohci)
@@ -3432,18 +3471,21 @@
                /* The ohci_soft_reset() stops all DMA contexts, so we
                 * dont need to do this.  */
                /* Free AR dma */
-               free_dma_rcv_ctx(&ohci->ar_req_context);
-               free_dma_rcv_ctx(&ohci->ar_resp_context);
+               free_dma_rcv_ctx(&ohci->ar_req_context, 
OHCI_FREE_DMA_CTX_DIRECT, NULL);
+               free_dma_rcv_ctx(&ohci->ar_resp_context, 
OHCI_FREE_DMA_CTX_DIRECT, NULL);
 
                /* Free AT dma */
                free_dma_trm_ctx(&ohci->at_req_context);
                free_dma_trm_ctx(&ohci->at_resp_context);
 
                /* Free IR dma */
-               free_dma_rcv_ctx(&ohci->ir_legacy_context);
+               free_dma_rcv_ctx(&ohci->ir_legacy_context, 
OHCI_FREE_DMA_CTX_DIRECT, NULL);
 
                /* Free IT dma */
                free_dma_trm_ctx(&ohci->it_legacy_context);
+               
+               /* Free work struct for IR Legacy DMA */
+               kfree(ohci->irlc_free_dma);
 
        case OHCI_INIT_HAVE_SELFID_BUFFER:
                pci_free_consistent(ohci->dev, OHCI1394_SI_DMA_BUF_SIZE,

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