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ath10k: fix diag_read to collect data for larger memory 

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: 68c03249f3 ('ath10k: convert pci_alloc_consistent() to dma_alloc_coherent()')
Signed-off-by: Ashok Raj Nagarajan <arnagara@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
This commit is contained in:
Ashok Raj Nagarajan 2016-05-28 11:25:40 +03:00 committed by Kalle Valo
parent 8a0a36cf98
commit 1e56d5127d
1 changed files with 16 additions and 12 deletions
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28
drivers/net/wireless/ath/ath10k/pci.c
View File

@ -869,7 +869,7 @@ 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;
@ -887,9 +887,10 @@ 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);
@ -897,9 +898,9 @@ 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,
@ -959,19 +960,22 @@ 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);