diag_read uses dma_alloc_coherent to allocate memory requested by the caller. If this memory requested is larger, more than DIAG_TRANSFER_LIMIT (2K), then it is likely that we may not get the requested memory and we would fail. To solve this, request dma_alloc_coherent for only DIAG_TRANSFER_LIMIT, and reuse this buffer multiple times as needed to copy the data requested in smaller chunks of size not more than DIAG_TRANSFER_LIMIT. Previously we were reading into the caller's only after getting the complete requested data. Fixes: 68c03249f388 ('ath10k: convert pci_alloc_consistent() to dma_alloc_coherent()') Signed-off-by: Ashok Raj Nagarajan <arnagara@xxxxxxxxxxxxxxxx> --- drivers/net/wireless/ath/ath10k/pci.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c index 8133d7b..8663a3b 100644 --- a/drivers/net/wireless/ath/ath10k/pci.c +++ b/drivers/net/wireless/ath/ath10k/pci.c @@ -864,7 +864,7 @@ static int ath10k_pci_diag_read_mem(struct ath10k *ar, u32 address, void *data, struct ath10k_pci *ar_pci = ath10k_pci_priv(ar); int ret = 0; u32 *buf; - unsigned int completed_nbytes, orig_nbytes, remaining_bytes; + unsigned int completed_nbytes, alloc_nbytes, remaining_bytes; struct ath10k_ce_pipe *ce_diag; /* Host buffer address in CE space */ u32 ce_data; @@ -882,9 +882,10 @@ static int ath10k_pci_diag_read_mem(struct ath10k *ar, u32 address, void *data, * 1) 4-byte alignment * 2) Buffer in DMA-able space */ - orig_nbytes = nbytes; + alloc_nbytes = min_t(unsigned int, nbytes, DIAG_TRANSFER_LIMIT); + data_buf = (unsigned char *)dma_alloc_coherent(ar->dev, - orig_nbytes, + alloc_nbytes, &ce_data_base, GFP_ATOMIC); @@ -892,9 +893,9 @@ static int ath10k_pci_diag_read_mem(struct ath10k *ar, u32 address, void *data, ret = -ENOMEM; goto done; } - memset(data_buf, 0, orig_nbytes); + memset(data_buf, 0, alloc_nbytes); - remaining_bytes = orig_nbytes; + remaining_bytes = nbytes; ce_data = ce_data_base; while (remaining_bytes) { nbytes = min_t(unsigned int, remaining_bytes, @@ -954,19 +955,22 @@ static int ath10k_pci_diag_read_mem(struct ath10k *ar, u32 address, void *data, } remaining_bytes -= nbytes; + + if (ret) { + ath10k_warn(ar, "failed to read diag value at 0x%x: %d\n", + address, ret); + break; + } + memcpy(data, data_buf, nbytes); + address += nbytes; - ce_data += nbytes; + data += nbytes; } done: - if (ret == 0) - memcpy(data, data_buf, orig_nbytes); - else - ath10k_warn(ar, "failed to read diag value at 0x%x: %d\n", - address, ret); if (data_buf) - dma_free_coherent(ar->dev, orig_nbytes, data_buf, + dma_free_coherent(ar->dev, alloc_nbytes, data_buf, ce_data_base); spin_unlock_bh(&ar_pci->ce_lock); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html