Re: [Bug #14016] mm/ipw2200 regression

Zhu Yi
2009-08-27T09:11:30Z

On Wed, 2009-08-26 at 22:44 +0800, Andrew Morton wrote:
>
> It is perhaps pretty simple to make the second (GFP_ATOMIC) allocation
> go away. The code is already conveniently structured to do this:
>
> do {
> chunk = (struct fw_chunk *)(data + offset);
> offset += sizeof(struct fw_chunk);
> /* build DMA packet and queue up for sending */
> /* dma to chunk->address, the chunk->length bytes from
> data +
> * offeset*/
> /* Dma loading */
> rc = ipw_fw_dma_add_buffer(priv, shared_phys + offset,
>
> le32_to_cpu(chunk->address),
>
> le32_to_cpu(chunk->length));
> if (rc) {
> IPW_DEBUG_INFO("dmaAddBuffer Failed\n");
> goto out;
> }
>
> offset += le32_to_cpu(chunk->length);
> } while (offset < len);
>
> what is the typical/expected value of chunk->length here? If it's
> significantly less than 4096*(2^6), could we convert this function to
> use a separate DMAable allocation per fw_chunk?

Unfortunately, the largest chunk size for the latest 3.1 firmware is
0x20040, which also requires order 6 page allocation. I'll try to use
the firmware DMA command block (64 slots) to handle the image (each for
4k, totally 256k).

Thanks,
-yi