Re: [PATCH v4] Add new mac80211 driver mwlwifi.

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2015-06-30 at 01:49 +0000, David Lin wrote:
> +++ b/drivers/net/wireless/mwlwifi/Kconfig
> @@ -0,0 +1,17 @@
> +config MWLWIFI
> +	tristate "Marvell Wireless WiFi driver (mwlwifi)"
> +	depends on PCI && MAC80211 && MWIFIEX_PCIE=n

I still think you need to get rid of this so we can build-test this
driver properly.

> +	select FW_LOADER
> +	select OF

This looks OK, though I get a very strange dependency loop warning from
Kconfig here.

Looks like the driver now builds almost cleanly with sparse/smatch on
64-bit.

Two warnings remain, both are bugs:

> writew(0x00, (void __iomem *)&priv->pcmd_buf[1]);

cannot be right. This memory isn't __iomem, it's dma_alloc_coherent, so
a simple write should be done.

in mwl_rx_ring_init:

>                         rx_hndl->psk_buff =
>                                 dev_alloc_skb(desc->rx_buf_size);
> 
>                         if (skb_linearize(rx_hndl->psk_buff)) {

*crash*. You also later check rx_hndl->psk_buff, but well after it
already crashed.

Also, this code sequence is utterly bogus. Please try to understand why
and then remove it.

You should also use paged RX since you're allocating *very large* buffe
rs. We found that even alloc_pages(1) will fail eventually, you're
doing an order-2 allocation here for every RX skb. At least used paged
RX to get it down to order-1.

johannes