From fce7c596c8bd726c07c09008134fa1ea9baceea1 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Wed, 20 Mar 2019 15:02:00 +0100 Subject: net: ks8851: Dequeue RX packets explicitly [ Upstream commit 536d3680fd2dab5c39857d62a3e084198fc74ff9 ] The ks8851 driver lets the chip auto-dequeue received packets once they have been read in full. It achieves that by setting the ADRFE flag in the RXQCR register ("Auto-Dequeue RXQ Frame Enable"). However if allocation of a packet's socket buffer or retrieval of the packet over the SPI bus fails, the packet will not have been read in full and is not auto-dequeued. Such partial retrieval of a packet confuses the chip's RX queue management: On the next RX interrupt, the first packet read from the queue will be the one left there previously and this one can be retrieved without issues. But for any newly received packets, the frame header status and byte count registers (RXFHSR and RXFHBCR) contain bogus values, preventing their retrieval. The chip allows explicitly dequeueing a packet from the RX queue by setting the RRXEF flag in the RXQCR register ("Release RX Error Frame"). This could be used to dequeue the packet in case of an error, but if that error is a failed SPI transfer, it is unknown if the packet was transferred in full and was auto-dequeued or if it was only transferred in part and requires an explicit dequeue. The safest approach is thus to always dequeue packets explicitly and forgo auto-dequeueing. Without this change, I've witnessed packet retrieval break completely when an SPI DMA transfer fails, requiring a chip reset. Explicit dequeueing magically fixes this and makes packet retrieval absolutely robust for me. The chip's documentation suggests auto-dequeuing and uses the RRXEF flag only to dequeue error frames which the driver doesn't want to retrieve. But that seems to be a fair-weather approach. Signed-off-by: Lukas Wunner Cc: Frank Pavlic Cc: Ben Dooks Cc: Tristram Ha Signed-off-by: David S. Miller Signed-off-by: Sasha Levin (Microsoft) --- drivers/net/ethernet/micrel/ks8851.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/net/ethernet/micrel/ks8851.c') diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c index 2fe96f1f3fe5..556666b0d756 100644 --- a/drivers/net/ethernet/micrel/ks8851.c +++ b/drivers/net/ethernet/micrel/ks8851.c @@ -526,9 +526,8 @@ static void ks8851_rx_pkts(struct ks8851_net *ks) /* set dma read address */ ks8851_wrreg16(ks, KS_RXFDPR, RXFDPR_RXFPAI | 0x00); - /* start the packet dma process, and set auto-dequeue rx */ - ks8851_wrreg16(ks, KS_RXQCR, - ks->rc_rxqcr | RXQCR_SDA | RXQCR_ADRFE); + /* start DMA access */ + ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA); if (rxlen > 4) { unsigned int rxalign; @@ -559,7 +558,8 @@ static void ks8851_rx_pkts(struct ks8851_net *ks) } } - ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr); + /* end DMA access and dequeue packet */ + ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_RRXEF); } } -- cgit v1.2.3 From 79b7bb03cd4675bc7383420c15281cecf5fb6466 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Wed, 20 Mar 2019 15:02:00 +0100 Subject: net: ks8851: Reassert reset pin if chip ID check fails [ Upstream commit 761cfa979a0c177d6c2d93ef5585cd79ae49a7d5 ] Commit 73fdeb82e963 ("net: ks8851: Add optional vdd_io regulator and reset gpio") amended the ks8851 driver to briefly assert the chip's reset pin on probe. It also amended the probe routine's error path to reassert the reset pin if a subsequent initialization step fails. However the commit misplaced reassertion of the reset pin in the error path such that it is not performed if the check of the Chip ID and Enable Register (CIDER) fails. The error path is therefore slightly asymmetrical to the probe routine's body. Fix it. Signed-off-by: Lukas Wunner Cc: Frank Pavlic Cc: Stephen Boyd Cc: Nishanth Menon Signed-off-by: David S. Miller Signed-off-by: Sasha Levin (Microsoft) --- drivers/net/ethernet/micrel/ks8851.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/ethernet/micrel/ks8851.c') diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c index 556666b0d756..546a79b9cb15 100644 --- a/drivers/net/ethernet/micrel/ks8851.c +++ b/drivers/net/ethernet/micrel/ks8851.c @@ -1545,9 +1545,9 @@ err_netdev: free_irq(ndev->irq, ks); err_irq: +err_id: if (gpio_is_valid(gpio)) gpio_set_value(gpio, 0); -err_id: regulator_disable(ks->vdd_reg); err_reg: regulator_disable(ks->vdd_io); -- cgit v1.2.3 From 64e8347986d0962dfbb335c5a6754bb261c69aa9 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Wed, 20 Mar 2019 15:02:00 +0100 Subject: net: ks8851: Delay requesting IRQ until opened [ Upstream commit d268f31552794abf5b6aa5af31021643411f25f5 ] The ks8851 driver currently requests the IRQ before registering the net_device. Because the net_device name is used as IRQ name and is still "eth%d" when the IRQ is requested, it's impossibe to tell IRQs apart if multiple ks8851 chips are present. Most other drivers delay requesting the IRQ until the net_device is opened. Do the same. The driver doesn't enable interrupts on the chip before opening the net_device and disables them when closing it, so there doesn't seem to be a need to request the IRQ already on probe. Signed-off-by: Lukas Wunner Cc: Frank Pavlic Cc: Ben Dooks Cc: Tristram Ha Signed-off-by: David S. Miller Signed-off-by: Sasha Levin (Microsoft) --- drivers/net/ethernet/micrel/ks8851.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) (limited to 'drivers/net/ethernet/micrel/ks8851.c') diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c index 546a79b9cb15..b8f20aa2b7ad 100644 --- a/drivers/net/ethernet/micrel/ks8851.c +++ b/drivers/net/ethernet/micrel/ks8851.c @@ -776,6 +776,15 @@ static void ks8851_tx_work(struct work_struct *work) static int ks8851_net_open(struct net_device *dev) { struct ks8851_net *ks = netdev_priv(dev); + int ret; + + ret = request_threaded_irq(dev->irq, NULL, ks8851_irq, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + dev->name, ks); + if (ret < 0) { + netdev_err(dev, "failed to get irq\n"); + return ret; + } /* lock the card, even if we may not actually be doing anything * else at the moment */ @@ -890,6 +899,8 @@ static int ks8851_net_stop(struct net_device *dev) dev_kfree_skb(txb); } + free_irq(dev->irq, ks); + return 0; } @@ -1520,14 +1531,6 @@ static int ks8851_probe(struct spi_device *spi) ks8851_read_selftest(ks); ks8851_init_mac(ks); - ret = request_threaded_irq(spi->irq, NULL, ks8851_irq, - IRQF_TRIGGER_LOW | IRQF_ONESHOT, - ndev->name, ks); - if (ret < 0) { - dev_err(&spi->dev, "failed to get irq\n"); - goto err_irq; - } - ret = register_netdev(ndev); if (ret) { dev_err(&spi->dev, "failed to register network device\n"); @@ -1540,11 +1543,7 @@ static int ks8851_probe(struct spi_device *spi) return 0; - err_netdev: - free_irq(ndev->irq, ks); - -err_irq: err_id: if (gpio_is_valid(gpio)) gpio_set_value(gpio, 0); @@ -1565,7 +1564,6 @@ static int ks8851_remove(struct spi_device *spi) dev_info(&spi->dev, "remove\n"); unregister_netdev(priv->netdev); - free_irq(spi->irq, priv); if (gpio_is_valid(priv->gpio)) gpio_set_value(priv->gpio, 0); regulator_disable(priv->vdd_reg); -- cgit v1.2.3 From b6ca8ec8bb742625e8b2e19e1fcbb3936a543cef Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Wed, 20 Mar 2019 15:02:00 +0100 Subject: net: ks8851: Set initial carrier state to down [ Upstream commit 9624bafa5f6418b9ca5b3f66d1f6a6a2e8bf6d4c ] The ks8851 chip's initial carrier state is down. A Link Change Interrupt is signaled once interrupts are enabled if the carrier is up. The ks8851 driver has it backwards by assuming that the initial carrier state is up. The state is therefore misrepresented if the interface is opened with no cable attached. Fix it. The Link Change interrupt is sometimes not signaled unless the P1MBSR register (which contains the Link Status bit) is read on ->ndo_open(). This might be a hardware erratum. Read the register by calling mii_check_link(), which has the desirable side effect of setting the carrier state to down if the cable was detached while the interface was closed. Signed-off-by: Lukas Wunner Cc: Frank Pavlic Cc: Ben Dooks Cc: Tristram Ha Signed-off-by: David S. Miller Signed-off-by: Sasha Levin (Microsoft) --- drivers/net/ethernet/micrel/ks8851.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/net/ethernet/micrel/ks8851.c') diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c index b8f20aa2b7ad..7ddaa7d88f1d 100644 --- a/drivers/net/ethernet/micrel/ks8851.c +++ b/drivers/net/ethernet/micrel/ks8851.c @@ -849,6 +849,7 @@ static int ks8851_net_open(struct net_device *dev) netif_dbg(ks, ifup, ks->netdev, "network device up\n"); mutex_unlock(&ks->lock); + mii_check_link(&ks->mii); return 0; } @@ -1510,6 +1511,7 @@ static int ks8851_probe(struct spi_device *spi) spi_set_drvdata(spi, ks); + netif_carrier_off(ks->netdev); ndev->if_port = IF_PORT_100BASET; ndev->netdev_ops = &ks8851_netdev_ops; ndev->irq = spi->irq; -- cgit v1.2.3