If an error occurs during the initialization in emac_dev_open() (the driver's ndo_open function), interrupts, DMA descriptors etc. must be freed. The current rollback code is buggy in several ways. 1) Freeing the interrupts. The current code will not free all interrupts that were requested by the driver. Furthermore, the code tries to do a platform_get_resource(priv->pdev, IORESOURCE_IRQ, -1) in its last iteration. This patch fixes these bugs. 2) Wrong order of err: and rollback: labels. If the setup of the PHY in the code fails, the interrupts that have been requested before are not freed: request irq if requesting irqs fails, goto rollback setup phy if phy setup fails, goto err return 0 rollback: free irqs err: This patch brings the code into the correct order. 3) The code calls napi_enable() and emac_int_enable(), but does not undo both in case of an error. This patch adds calls of emac_int_disable() and napi_disable() to the rollback code. 4) RX DMA descriptors are not freed in case of an error: Right before requesting the irqs, the function creates DMA descriptors for the RX channel. These RX descriptors are never freed when we jump to either rollback or err. This patch adds code for freeing the DMA descriptors in the case of an initialization error. This required a modification of cpdma_ctrl_stop() in davinci_cpdma.c: We must be able to call this function to free the DMA descriptors while the DMA channels are in IDLE state (before cpdma_ctlr_start() was called). Tested on a custom board with the Texas Instruments AM1808.
Unified · Split
| @@ -355,7 +355,7 @@ int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr) · 354 unmodified lines | ||
| 355 | 355 | int i; |
| 356 | 356 | |
| 357 | 357 | spin_lock_irqsave(&ctlr->lock, flags); |
| 358 | − if (ctlr->state != CPDMA_STATE_ACTIVE) { | |
| 358 | + if (ctlr->state == CPDMA_STATE_TEARDOWN) { | |
| 359 | 359 | spin_unlock_irqrestore(&ctlr->lock, flags); |
| 360 | 360 | return -EINVAL; |
| 361 | 361 | } |
| @@ -891,7 +891,7 @@ int cpdma_chan_stop(struct cpdma_chan *chan) · 529 unmodified lines | ||
| 891 | 891 | unsigned timeout; |
| 892 | 892 | |
| 893 | 893 | spin_lock_irqsave(&chan->lock, flags); |
| 894 | − if (chan->state != CPDMA_STATE_ACTIVE) { | |
| 894 | + if (chan->state == CPDMA_STATE_TEARDOWN) { | |
| 895 | 895 | spin_unlock_irqrestore(&chan->lock, flags); |
| 896 | 896 | return -EINVAL; |
| 897 | 897 | } |
| @@ -1533,8 +1533,8 @@ static int emac_dev_open(struct net_device *ndev) · 1532 unmodified lines | ||
| 1533 | 1533 | u32 cnt; |
| 1534 | 1534 | struct resource *res; |
| 1535 | 1535 | int q, m, ret; |
| 1536 | + int res_num = 0, irq_num = 0; | |
| 1536 | 1537 | int i = 0; |
| 1537 | − int k = 0; | |
| 1538 | 1538 | struct emac_priv *priv = netdev_priv(ndev); |
| 1539 | 1539 | |
| 1540 | 1540 | pm_runtime_get(&priv->pdev->dev); |
| @@ -1564,14 +1564,24 @@ static int emac_dev_open(struct net_device *ndev) · 23 unmodified lines | ||
| 1564 | 1564 | } |
| 1565 | 1565 | |
| 1566 | 1566 | /* Request IRQ */ |
| 1567 | + while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, | |
| 1568 | + res_num))) { | |
| 1569 | + for (irq_num = res->start; irq_num <= res->end; irq_num++) { | |
| 1570 | + dev_err(emac_dev, "Request IRQ %d\n", irq_num); | |
| 1571 | + if (request_irq(irq_num, emac_irq, 0, ndev->name, | |
| 1572 | + ndev)) { | |
| 1573 | + dev_err(emac_dev, | |
| 1574 | + "DaVinci EMAC: request_irq() failed\n"); | |
| 1575 | + ret = -EBUSY; | |
| 1567 | 1576 | |
| 1568 | − while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k))) { | |
| 1569 | − for (i = res->start; i <= res->end; i++) { | |
| 1570 | − if (request_irq(i, emac_irq, 0, ndev->name, ndev)) | |
| 1571 | 1577 | goto rollback; |
| 1578 | + } | |
| 1572 | 1579 | } |
| 1573 | − k++; | |
| 1580 | + res_num++; | |
| 1574 | 1581 | } |
| 1582 | + /* prepare counters for rollback in case of an error */ | |
| 1583 | + res_num--; | |
| 1584 | + irq_num--; | |
| 1575 | 1585 | |
| 1576 | 1586 | /* Start/Enable EMAC hardware */ |
| 1577 | 1587 | emac_hw_enable(priv); |
| @@ -1638,19 +1648,23 @@ static int emac_dev_open(struct net_device *ndev) · 60 unmodified lines | ||
| 1638 | 1648 | |
| 1639 | 1649 | return 0; |
| 1640 | 1650 | |
| 1641 | −rollback: | |
| 1642 | − | |
| 1643 | − dev_err(emac_dev, "DaVinci EMAC: request_irq() failed"); | |
| 1651 | +err: | |
| 1652 | + emac_int_disable(priv); | |
| 1653 | + napi_disable(&priv->napi); | |
| 1644 | 1654 | |
| 1645 | − for (q = k; k >= 0; k--) { | |
| 1646 | − for (m = i; m >= res->start; m--) | |
| 1655 | +rollback: | |
| 1656 | + for (q = res_num; q >= 0; q--) { | |
| 1657 | + res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, q); | |
| 1658 | + /* at the first iteration, irq_num is already set to the | |
| 1659 | + * right value | |
| 1660 | + */ | |
| 1661 | + if (q != res_num) | |
| 1662 | + irq_num = res->end; | |
| 1663 | + | |
| 1664 | + for (m = irq_num; m >= res->start; m--) | |
| 1647 | 1665 | free_irq(m, ndev); |
| 1648 | − res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1); | |
| 1649 | − m = res->end; | |
| 1650 | 1666 | } |
| 1651 | − | |
| 1652 | − ret = -EBUSY; | |
| 1653 | −err: | |
| 1667 | + cpdma_ctlr_stop(priv->dma); | |
| 1654 | 1668 | pm_runtime_put(&priv->pdev->dev); |
| 1655 | 1669 | return ret; |
| 1656 | 1670 | } |