From 47f070a63e735bcc8d481de31be1b5a1aa62b31c Mon Sep 17 00:00:00 2001 From: Duoming Zhou Date: Mon, 25 Apr 2022 12:24:00 +0800 Subject: can: grcan: grcan_close(): fix deadlock There are deadlocks caused by del_timer_sync(&priv->hang_timer) and del_timer_sync(&priv->rr_timer) in grcan_close(), one of the deadlocks are shown below: (Thread 1) | (Thread 2) | grcan_reset_timer() grcan_close() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) ... | grcan_initiate_running_reset() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | ... We hold priv->lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need priv->lock in position (2) of thread 2. As a result, grcan_close() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_irqsave(), which could let timer handler to obtain the needed lock. Link: https://lore.kernel.org/all/20220425042400.66517-1-duoming@zju.edu.cn Fixes: 6cec9b07fe6a ("can: grcan: Add device driver for GRCAN and GRHCAN cores") Cc: stable@vger.kernel.org Signed-off-by: Duoming Zhou Reviewed-by: Andreas Larsson Signed-off-by: Marc Kleine-Budde --- drivers/net/can/grcan.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers') diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c index d0c5a7a60daf..1189057b5d68 100644 --- a/drivers/net/can/grcan.c +++ b/drivers/net/can/grcan.c @@ -1102,8 +1102,10 @@ static int grcan_close(struct net_device *dev) priv->closing = true; if (priv->need_txbug_workaround) { + spin_unlock_irqrestore(&priv->lock, flags); del_timer_sync(&priv->hang_timer); del_timer_sync(&priv->rr_timer); + spin_lock_irqsave(&priv->lock, flags); } netif_stop_queue(dev); grcan_stop_hardware(dev); -- cgit v1.2.3 From 101da4268626b00d16356a6bf284d66e44c46ff9 Mon Sep 17 00:00:00 2001 From: Daniel Hellstrom Date: Fri, 29 Apr 2022 10:46:54 +0200 Subject: can: grcan: use ofdev->dev when allocating DMA memory Use the device of the device tree node should be rather than the device of the struct net_device when allocating DMA buffers. The driver got away with it on sparc32 until commit 53b7670e5735 ("sparc: factor the dma coherent mapping into helper") after which the driver oopses. Fixes: 6cec9b07fe6a ("can: grcan: Add device driver for GRCAN and GRHCAN cores") Link: https://lore.kernel.org/all/20220429084656.29788-2-andreas@gaisler.com Cc: stable@vger.kernel.org Signed-off-by: Daniel Hellstrom Signed-off-by: Andreas Larsson Signed-off-by: Marc Kleine-Budde --- drivers/net/can/grcan.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c index 1189057b5d68..f8860900575b 100644 --- a/drivers/net/can/grcan.c +++ b/drivers/net/can/grcan.c @@ -248,6 +248,7 @@ struct grcan_device_config { struct grcan_priv { struct can_priv can; /* must be the first member */ struct net_device *dev; + struct device *ofdev_dev; struct napi_struct napi; struct grcan_registers __iomem *regs; /* ioremap'ed registers */ @@ -921,7 +922,7 @@ static void grcan_free_dma_buffers(struct net_device *dev) struct grcan_priv *priv = netdev_priv(dev); struct grcan_dma *dma = &priv->dma; - dma_free_coherent(&dev->dev, dma->base_size, dma->base_buf, + dma_free_coherent(priv->ofdev_dev, dma->base_size, dma->base_buf, dma->base_handle); memset(dma, 0, sizeof(*dma)); } @@ -946,7 +947,7 @@ static int grcan_allocate_dma_buffers(struct net_device *dev, /* Extra GRCAN_BUFFER_ALIGNMENT to allow for alignment */ dma->base_size = lsize + ssize + GRCAN_BUFFER_ALIGNMENT; - dma->base_buf = dma_alloc_coherent(&dev->dev, + dma->base_buf = dma_alloc_coherent(priv->ofdev_dev, dma->base_size, &dma->base_handle, GFP_KERNEL); @@ -1589,6 +1590,7 @@ static int grcan_setup_netdev(struct platform_device *ofdev, memcpy(&priv->config, &grcan_module_config, sizeof(struct grcan_device_config)); priv->dev = dev; + priv->ofdev_dev = &ofdev->dev; priv->regs = base; priv->can.bittiming_const = &grcan_bittiming_const; priv->can.do_set_bittiming = grcan_set_bittiming; -- cgit v1.2.3 From 1e93ed26acf03fe6c97c6d573a10178596aadd43 Mon Sep 17 00:00:00 2001 From: Andreas Larsson Date: Fri, 29 Apr 2022 10:46:55 +0200 Subject: can: grcan: grcan_probe(): fix broken system id check for errata workaround needs The systemid property was checked for in the wrong place of the device tree and compared to the wrong value. Fixes: 6cec9b07fe6a ("can: grcan: Add device driver for GRCAN and GRHCAN cores") Link: https://lore.kernel.org/all/20220429084656.29788-3-andreas@gaisler.com Cc: stable@vger.kernel.org Signed-off-by: Andreas Larsson Signed-off-by: Marc Kleine-Budde --- drivers/net/can/grcan.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c index f8860900575b..4ca3da56d3aa 100644 --- a/drivers/net/can/grcan.c +++ b/drivers/net/can/grcan.c @@ -241,7 +241,7 @@ struct grcan_device_config { .rxsize = GRCAN_DEFAULT_BUFFER_SIZE, \ } -#define GRCAN_TXBUG_SAFE_GRLIB_VERSION 0x4100 +#define GRCAN_TXBUG_SAFE_GRLIB_VERSION 4100 #define GRLIB_VERSION_MASK 0xffff /* GRCAN private data structure */ @@ -1643,6 +1643,7 @@ exit_free_candev: static int grcan_probe(struct platform_device *ofdev) { struct device_node *np = ofdev->dev.of_node; + struct device_node *sysid_parent; u32 sysid, ambafreq; int irq, err; void __iomem *base; @@ -1651,10 +1652,15 @@ static int grcan_probe(struct platform_device *ofdev) /* Compare GRLIB version number with the first that does not * have the tx bug (see start_xmit) */ - err = of_property_read_u32(np, "systemid", &sysid); - if (!err && ((sysid & GRLIB_VERSION_MASK) - >= GRCAN_TXBUG_SAFE_GRLIB_VERSION)) - txbug = false; + sysid_parent = of_find_node_by_path("/ambapp0"); + if (sysid_parent) { + of_node_get(sysid_parent); + err = of_property_read_u32(sysid_parent, "systemid", &sysid); + if (!err && ((sysid & GRLIB_VERSION_MASK) >= + GRCAN_TXBUG_SAFE_GRLIB_VERSION)) + txbug = false; + of_node_put(sysid_parent); + } err = of_property_read_u32(np, "freq", &ambafreq); if (err) { -- cgit v1.2.3 From 2873d4d52f7c52d60b316ba6c47bd7122b5a9861 Mon Sep 17 00:00:00 2001 From: Andreas Larsson Date: Fri, 29 Apr 2022 10:46:56 +0200 Subject: can: grcan: only use the NAPI poll budget for RX The previous split budget between TX and RX made it return not using the entire budget but at the same time not having calling called napi_complete. This sometimes led to the poll to not be called, and at the same time having TX and RX interrupts disabled resulting in the driver getting stuck. Fixes: 6cec9b07fe6a ("can: grcan: Add device driver for GRCAN and GRHCAN cores") Link: https://lore.kernel.org/all/20220429084656.29788-4-andreas@gaisler.com Cc: stable@vger.kernel.org Signed-off-by: Andreas Larsson Signed-off-by: Marc Kleine-Budde --- drivers/net/can/grcan.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) (limited to 'drivers') diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c index 4ca3da56d3aa..5215bd9b2c80 100644 --- a/drivers/net/can/grcan.c +++ b/drivers/net/can/grcan.c @@ -1125,7 +1125,7 @@ static int grcan_close(struct net_device *dev) return 0; } -static int grcan_transmit_catch_up(struct net_device *dev, int budget) +static void grcan_transmit_catch_up(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); unsigned long flags; @@ -1133,7 +1133,7 @@ static int grcan_transmit_catch_up(struct net_device *dev, int budget) spin_lock_irqsave(&priv->lock, flags); - work_done = catch_up_echo_skb(dev, budget, true); + work_done = catch_up_echo_skb(dev, -1, true); if (work_done) { if (!priv->resetting && !priv->closing && !(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)) @@ -1147,8 +1147,6 @@ static int grcan_transmit_catch_up(struct net_device *dev, int budget) } spin_unlock_irqrestore(&priv->lock, flags); - - return work_done; } static int grcan_receive(struct net_device *dev, int budget) @@ -1230,19 +1228,13 @@ static int grcan_poll(struct napi_struct *napi, int budget) struct net_device *dev = priv->dev; struct grcan_registers __iomem *regs = priv->regs; unsigned long flags; - int tx_work_done, rx_work_done; - int rx_budget = budget / 2; - int tx_budget = budget - rx_budget; + int work_done; - /* Half of the budget for receiving messages */ - rx_work_done = grcan_receive(dev, rx_budget); + work_done = grcan_receive(dev, budget); - /* Half of the budget for transmitting messages as that can trigger echo - * frames being received - */ - tx_work_done = grcan_transmit_catch_up(dev, tx_budget); + grcan_transmit_catch_up(dev); - if (rx_work_done < rx_budget && tx_work_done < tx_budget) { + if (work_done < budget) { napi_complete(napi); /* Guarantee no interference with a running reset that otherwise @@ -1259,7 +1251,7 @@ static int grcan_poll(struct napi_struct *napi, int budget) spin_unlock_irqrestore(&priv->lock, flags); } - return rx_work_done + tx_work_done; + return work_done; } /* Work tx bug by waiting while for the risky situation to clear. If that fails, -- cgit v1.2.3