Subject: Re: Keystone 2 boards boot failure

From: Franklin Cooper <[email-masked]>
Date: Tue, 2 Feb 2016 16:59:34 -0600

On 02/02/2016 03:26 PM, Arnd Bergmann wrote:
> On Tuesday 02 February 2016 15:01:33 Franklin S Cooper Jr. wrote:
>>
>> Yes. Here is a boot log on the latest master with the below
>> three patches reverted.
>> http://pastebin.com/W7RWSHpE (Working)
>>
>> I reverted these three patches. The two latest patches seem
>> to be trying to correct/expand upon the last patch on this list.
>>
>> commit 958d104e3d40eef5148c402887138f6594ff7e1e
>> netcp: fix regression in receive processing
>>
>> commit 9dd2d6c5c9755b160fe0111bcdad9491676feea8
>> netcp: add more __le32 annotations
>>
>> commit 899077791403ff7a2d8cfaa87bd1a82d729463e2
>> netcp: try to reduce type confusion in descriptors
>>
> 
> The middle patch should have no effect on generated code, so I'm ignoring
> that for now.
> 
> The next thing to rule out is an endianess bug. I assume you
> are running this on with a little-endian kernel, correct? If
> you are running big-endian, the base assumption that the driver needs
> to swap the data was flawed and that portion needs to be done.
> 
> If you are running little-endian 32-bit, please try the partial
> revert below, which just undoes the attempt to make it work with
> 64-bit kernels.

Keystone 2 devices are little-endian 32-bit devices.

This partial revert fixes the boot problem for me.
> 
> 	Arnd
> 	
> diff --git a/drivers/net/ethernet/ti/netcp_core.c b/drivers/net/ethernet/ti/netcp_core.c
> index c61d66d38634..7e291c04a81a 100644
> --- a/drivers/net/ethernet/ti/netcp_core.c
> +++ b/drivers/net/ethernet/ti/netcp_core.c
> @@ -117,20 +117,10 @@ static void get_pkt_info(dma_addr_t *buff, u32 *buff_len, dma_addr_t *ndesc,
>  	*ndesc = le32_to_cpu(desc->next_desc);
>  }
>  
> -static void get_pad_info(u32 *pad0, u32 *pad1, u32 *pad2, struct knav_dma_desc *desc)
> +static void get_pad_info(u32 *pad0, u32 *pad1, struct knav_dma_desc *desc)
>  {
>  	*pad0 = le32_to_cpu(desc->pad[0]);
>  	*pad1 = le32_to_cpu(desc->pad[1]);
> -	*pad2 = le32_to_cpu(desc->pad[2]);
> -}
> -
> -static void get_pad_ptr(void **padptr, struct knav_dma_desc *desc)
> -{
> -	u64 pad64;
> -
> -	pad64 = le32_to_cpu(desc->pad[0]) +
> -		((u64)le32_to_cpu(desc->pad[1]) << 32);
> -	*padptr = (void *)(uintptr_t)pad64;
>  }
>  
>  static void get_org_pkt_info(dma_addr_t *buff, u32 *buff_len,
> @@ -163,11 +153,10 @@ static void set_desc_info(u32 desc_info, u32 pkt_info,
>  	desc->packet_info = cpu_to_le32(pkt_info);
>  }
>  
> -static void set_pad_info(u32 pad0, u32 pad1, u32 pad2, struct knav_dma_desc *desc)
> +static void set_pad_info(u32 pad0, u32 pad1, struct knav_dma_desc *desc)
>  {
>  	desc->pad[0] = cpu_to_le32(pad0);
>  	desc->pad[1] = cpu_to_le32(pad1);
> -	desc->pad[2] = cpu_to_le32(pad1);
>  }
>  
>  static void set_org_pkt_info(dma_addr_t buff, u32 buff_len,
> @@ -581,7 +570,6 @@ static void netcp_free_rx_desc_chain(struct netcp_intf *netcp,
>  	dma_addr_t dma_desc, dma_buf;
>  	unsigned int buf_len, dma_sz = sizeof(*ndesc);
>  	void *buf_ptr;
> -	u32 pad[2];
>  	u32 tmp;
>  
>  	get_words(&dma_desc, 1, &desc->next_desc);
> @@ -593,15 +581,13 @@ static void netcp_free_rx_desc_chain(struct netcp_intf *netcp,
>  			break;
>  		}
>  		get_pkt_info(&dma_buf, &tmp, &dma_desc, ndesc);
> -		get_pad_ptr(&buf_ptr, ndesc);
> +		get_pad_info((u32 *)&buf_ptr, &tmp, ndesc);
>  		dma_unmap_page(netcp->dev, dma_buf, PAGE_SIZE, DMA_FROM_DEVICE);
>  		__free_page(buf_ptr);
>  		knav_pool_desc_put(netcp->rx_pool, desc);
>  	}
>  
> -	get_pad_info(&pad[0], &pad[1], &buf_len, desc);
> -	buf_ptr = (void *)(uintptr_t)(pad[0] + ((u64)pad[1] << 32));
> -
> +	get_pad_info((u32 *)&buf_ptr, &buf_len, desc);
>  	if (buf_ptr)
>  		netcp_frag_free(buf_len <= PAGE_SIZE, buf_ptr);
>  	knav_pool_desc_put(netcp->rx_pool, desc);
> @@ -639,8 +625,8 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
>  	dma_addr_t dma_desc, dma_buff;
>  	struct netcp_packet p_info;
>  	struct sk_buff *skb;
> -	u32 pad[2];
>  	void *org_buf_ptr;
> +	u32 tmp;
>  
>  	dma_desc = knav_queue_pop(netcp->rx_queue, &dma_sz);
>  	if (!dma_desc)
> @@ -653,8 +639,7 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
>  	}
>  
>  	get_pkt_info(&dma_buff, &buf_len, &dma_desc, desc);
> -	get_pad_info(&pad[0], &pad[1], &org_buf_len, desc);
> -	org_buf_ptr = (void *)(uintptr_t)(pad[0] + ((u64)pad[1] << 32));
> +	get_pad_info((u32 *)&org_buf_ptr, &org_buf_len, desc);
>  
>  	if (unlikely(!org_buf_ptr)) {
>  		dev_err(netcp->ndev_dev, "NULL bufptr in desc\n");
> @@ -679,7 +664,6 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
>  	/* Fill in the page fragment list */
>  	while (dma_desc) {
>  		struct page *page;
> -		void *ptr;
>  
>  		ndesc = knav_pool_desc_unmap(netcp->rx_pool, dma_desc, dma_sz);
>  		if (unlikely(!ndesc)) {
> @@ -688,8 +672,7 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
>  		}
>  
>  		get_pkt_info(&dma_buff, &buf_len, &dma_desc, ndesc);
> -		get_pad_ptr(&ptr, ndesc);
> -		page = ptr;
> +		get_pad_info((u32 *)&page, &tmp, ndesc);
>  
>  		if (likely(dma_buff && buf_len && page)) {
>  			dma_unmap_page(netcp->dev, dma_buff, PAGE_SIZE,
> @@ -767,6 +750,7 @@ static void netcp_free_rx_buf(struct netcp_intf *netcp, int fdq)
>  	unsigned int buf_len, dma_sz;
>  	dma_addr_t dma;
>  	void *buf_ptr;
> +	u32 tmp;
>  
>  	/* Allocate descriptor */
>  	while ((dma = knav_queue_pop(netcp->rx_fdq[fdq], &dma_sz))) {
> @@ -777,7 +761,7 @@ static void netcp_free_rx_buf(struct netcp_intf *netcp, int fdq)
>  		}
>  
>  		get_org_pkt_info(&dma, &buf_len, desc);
> -		get_pad_ptr(&buf_ptr, desc);
> +		get_pad_info((u32 *)&buf_ptr, &tmp, desc);
>  
>  		if (unlikely(!dma)) {
>  			dev_err(netcp->ndev_dev, "NULL orig_buff in desc\n");
> @@ -829,7 +813,7 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq)
>  	struct page *page;
>  	dma_addr_t dma;
>  	void *bufptr;
> -	u32 pad[3];
> +	u32 pad[2];
>  
>  	/* Allocate descriptor */
>  	hwdesc = knav_pool_desc_get(netcp->rx_pool);
> @@ -846,7 +830,7 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq)
>  				SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
>  
>  		bufptr = netdev_alloc_frag(primary_buf_len);
> -		pad[2] = primary_buf_len;
> +		pad[1] = primary_buf_len;
>  
>  		if (unlikely(!bufptr)) {
>  			dev_warn_ratelimited(netcp->ndev_dev,
> @@ -858,8 +842,7 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq)
>  		if (unlikely(dma_mapping_error(netcp->dev, dma)))
>  			goto fail;
>  
> -		pad[0] = lower_32_bits((uintptr_t)bufptr);
> -		pad[1] = upper_32_bits((uintptr_t)bufptr);
> +		pad[0] = (u32)bufptr;
>  
>  	} else {
>  		/* Allocate a secondary receive queue entry */
> @@ -870,9 +853,8 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq)
>  		}
>  		buf_len = PAGE_SIZE;
>  		dma = dma_map_page(netcp->dev, page, 0, buf_len, DMA_TO_DEVICE);
> -		pad[0] = lower_32_bits(dma);
> -		pad[1] = upper_32_bits(dma);
> -		pad[2] = 0;
> +		pad[0] = (u32)page;
> +		pad[1] = 0;
>  	}
>  
>  	desc_info =  KNAV_DMA_DESC_PS_INFO_IN_DESC;
> @@ -882,7 +864,7 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq)
>  	pkt_info |= (netcp->rx_queue_id & KNAV_DMA_DESC_RETQ_MASK) <<
>  		    KNAV_DMA_DESC_RETQ_SHIFT;
>  	set_org_pkt_info(dma, buf_len, hwdesc);
> -	set_pad_info(pad[0], pad[1], pad[2], hwdesc);
> +	set_pad_info(pad[0], pad[1], hwdesc);
>  	set_desc_info(desc_info, pkt_info, hwdesc);
>  
>  	/* Push to FDQs */
> @@ -971,11 +953,11 @@ static int netcp_process_tx_compl_packets(struct netcp_intf *netcp,
>  					  unsigned int budget)
>  {
>  	struct knav_dma_desc *desc;
> -	void *ptr;
>  	struct sk_buff *skb;
>  	unsigned int dma_sz;
>  	dma_addr_t dma;
>  	int pkts = 0;
> +	u32 tmp;
>  
>  	while (budget--) {
>  		dma = knav_queue_pop(netcp->tx_compl_q, &dma_sz);
> @@ -988,8 +970,7 @@ static int netcp_process_tx_compl_packets(struct netcp_intf *netcp,
>  			continue;
>  		}
>  
> -		get_pad_ptr(&ptr, desc);
> -		skb = ptr;
> +		get_pad_info((u32 *)&skb, &tmp, desc);
>  		netcp_free_tx_desc_chain(netcp, desc, dma_sz);
>  		if (!skb) {
>  			dev_err(netcp->ndev_dev, "No skb in Tx desc\n");
> @@ -1078,7 +1059,6 @@ netcp_tx_map_skb(struct sk_buff *skb, struct netcp_intf *netcp)
>  		u32 page_offset = frag->page_offset;
>  		u32 buf_len = skb_frag_size(frag);
>  		dma_addr_t desc_dma;
> -		u32 desc_dma_32;
>  		u32 pkt_info;
>  
>  		dma_addr = dma_map_page(dev, page, page_offset, buf_len,
> @@ -1100,8 +1080,7 @@ netcp_tx_map_skb(struct sk_buff *skb, struct netcp_intf *netcp)
>  			(netcp->tx_compl_qid & KNAV_DMA_DESC_RETQ_MASK) <<
>  				KNAV_DMA_DESC_RETQ_SHIFT;
>  		set_pkt_info(dma_addr, buf_len, 0, ndesc);
> -		desc_dma_32 = (u32)desc_dma;
> -		set_words(&desc_dma_32, 1, &pdesc->next_desc);
> +		set_words(&desc_dma, 1, &pdesc->next_desc);
>  		pkt_len += buf_len;
>  		if (pdesc != desc)
>  			knav_pool_desc_map(netcp->tx_pool, pdesc,
> @@ -1194,10 +1173,7 @@ static int netcp_tx_submit_skb(struct netcp_intf *netcp,
>  	}
>  
>  	set_words(&tmp, 1, &desc->packet_info);
> -	tmp = lower_32_bits((uintptr_t)&skb);
> -	set_words(&tmp, 1, &desc->pad[0]);
> -	tmp = upper_32_bits((uintptr_t)&skb);
> -	set_words(&tmp, 1, &desc->pad[1]);
> +	set_words((u32 *)&skb, 1, &desc->pad[0]);
>  
>  	if (tx_pipe->flags & SWITCH_TO_PORT_IN_TAGINFO) {
>  		tmp = tx_pipe->switch_to_port;
>