4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Allen Hubbe <Allen.Hubbe@xxxxxxxx> commit 88931ec3dc11e7dbceb3b0df455693873b508fbe upstream. Do not sleep in ntb_async_tx_submit, which could deadlock. This reverts commit "8c874cc140d667f84ae4642bb5b5e0d6396d2ca4" Fixes: 8c874cc140d6 ("NTB: Address out of DMA descriptor issue with NTB") Reported-by: Jia-Ju Bai <baijiaju1990@xxxxxxx> Signed-off-by: Allen Hubbe <Allen.Hubbe@xxxxxxxx> Acked-by: Dave Jiang <dave.jiang@xxxxxxxxx> Signed-off-by: Jon Mason <jdmason@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/ntb/ntb_transport.c | 50 ++++++-------------------------------------- 1 file changed, 7 insertions(+), 43 deletions(-) --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -176,14 +176,12 @@ struct ntb_transport_qp { u64 rx_err_ver; u64 rx_memcpy; u64 rx_async; - u64 dma_rx_prep_err; u64 tx_bytes; u64 tx_pkts; u64 tx_ring_full; u64 tx_err_no_buf; u64 tx_memcpy; u64 tx_async; - u64 dma_tx_prep_err; }; struct ntb_transport_mw { @@ -256,8 +254,6 @@ enum { #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count) #define NTB_QP_DEF_NUM_ENTRIES 100 #define NTB_LINK_DOWN_TIMEOUT 10 -#define DMA_RETRIES 20 -#define DMA_OUT_RESOURCE_TO msecs_to_jiffies(50) static void ntb_transport_rxc_db(unsigned long data); static const struct ntb_ctx_ops ntb_transport_ops; @@ -518,12 +514,6 @@ static ssize_t debugfs_read(struct file out_offset += snprintf(buf + out_offset, out_count - out_offset, "free tx - \t%u\n", ntb_transport_tx_free_entry(qp)); - out_offset += snprintf(buf + out_offset, out_count - out_offset, - "DMA tx prep err - \t%llu\n", - qp->dma_tx_prep_err); - out_offset += snprintf(buf + out_offset, out_count - out_offset, - "DMA rx prep err - \t%llu\n", - qp->dma_rx_prep_err); out_offset += snprintf(buf + out_offset, out_count - out_offset, "\n"); @@ -770,8 +760,6 @@ static void ntb_qp_link_down_reset(struc qp->tx_err_no_buf = 0; qp->tx_memcpy = 0; qp->tx_async = 0; - qp->dma_tx_prep_err = 0; - qp->dma_rx_prep_err = 0; } static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp) @@ -1314,7 +1302,6 @@ static int ntb_async_rx_submit(struct nt struct dmaengine_unmap_data *unmap; dma_cookie_t cookie; void *buf = entry->buf; - int retries = 0; len = entry->len; device = chan->device; @@ -1343,22 +1330,11 @@ static int ntb_async_rx_submit(struct nt unmap->from_cnt = 1; - for (retries = 0; retries < DMA_RETRIES; retries++) { - txd = device->device_prep_dma_memcpy(chan, - unmap->addr[1], - unmap->addr[0], len, - DMA_PREP_INTERRUPT); - if (txd) - break; - - set_current_state(TASK_INTERRUPTIBLE); - schedule_timeout(DMA_OUT_RESOURCE_TO); - } - - if (!txd) { - qp->dma_rx_prep_err++; + txd = device->device_prep_dma_memcpy(chan, unmap->addr[1], + unmap->addr[0], len, + DMA_PREP_INTERRUPT); + if (!txd) goto err_get_unmap; - } txd->callback_result = ntb_rx_copy_callback; txd->callback_param = entry; @@ -1603,7 +1579,6 @@ static int ntb_async_tx_submit(struct nt struct dmaengine_unmap_data *unmap; dma_addr_t dest; dma_cookie_t cookie; - int retries = 0; device = chan->device; dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index; @@ -1625,21 +1600,10 @@ static int ntb_async_tx_submit(struct nt unmap->to_cnt = 1; - for (retries = 0; retries < DMA_RETRIES; retries++) { - txd = device->device_prep_dma_memcpy(chan, dest, - unmap->addr[0], len, - DMA_PREP_INTERRUPT); - if (txd) - break; - - set_current_state(TASK_INTERRUPTIBLE); - schedule_timeout(DMA_OUT_RESOURCE_TO); - } - - if (!txd) { - qp->dma_tx_prep_err++; + txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len, + DMA_PREP_INTERRUPT); + if (!txd) goto err_get_unmap; - } txd->callback_result = ntb_tx_copy_callback; txd->callback_param = entry;