RE: [EXT] Re: [PATCH 00/43] wifi: nxpwifi: create nxpwifi to support iw61x

[David Lin]

Hi Johannes,

> From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> Sent: Saturday, June 22, 2024 2:20 AM
> To: David Lin <yu-hao.lin@xxxxxxx>; linux-wireless@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; briannorris@xxxxxxxxxxxx;
> kvalo@xxxxxxxxxx; francesco@xxxxxxxxxx; Pete Hsieh
> <tsung-hsien.hsieh@xxxxxxx>
> Subject: [EXT] Re: [PATCH 00/43] wifi: nxpwifi: create nxpwifi to support iw61x
> 
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> 
> On Fri, 2024-06-21 at 15:51 +0800, David Lin wrote:
> >
> >   wifi: nxpwifi: add ioctl.h
> 
> even the name here sounds questionable :)
> 
> >  48 files changed, 34928 insertions(+)
> >
> 
> This is ... huge. I don't know who could possibly review it at all.
> 
> A quick look suggests that it's got a bunch of things we probably really don't
> want to do that way any more, like
> 
> using semaphores in a wifi driver:
> 
> > +#include <linux/semaphore.h>
> 
> having a bunch of (sometimes wrong!) element definitions in a driver:
> 
> > +struct ieee_types_aid {
> ...
> > +     u16 aid;
> 
> embedding a (default?) wireless_dev when clearly the driver supports more
> than one netdev/wdev:
> 
> > +     struct wireless_dev wdev;
> 
> Having multiple own workqueues is probably also unreasonable:
> 
> > +     struct workqueue_struct *dfs_cac_workqueue;
> > +     struct workqueue_struct *dfs_chan_sw_workqueue;
> > +     struct workqueue_struct *workqueue;
> > +     struct workqueue_struct *rx_workqueue;
> > +     struct workqueue_struct *host_mlme_workqueue;
> 
> as is a misnamed mutex, but really you could use wiphy work and likely not
> have a mutex at all:
> 
> > +     /* mutex for scan */
> > +     struct mutex async_mutex;
> 
> (even mac80211 only has one mutex left, and that's for a specific case where
> otherwise we have some issues!)
> 
> questionable locking schemes, as evidenced simply by "is something locked"
> variables existing:
> 
> > +     bool rx_locked;
> > +     bool main_locked;
> 
> locking code, rather than data?
> 
> > +     /* spin lock for main process */
> > +     spinlock_t main_proc_lock;
> 
> but also simple things like not wanting to use ERR_PTR()?
> 
> > +static int nxpwifi_register(void *card, struct device *dev,
> > +                         struct nxpwifi_if_ops *if_ops, void
> > +**padapter)
> 
> (padapter is an out parameter)
> 
> Why random numbers for cookies instead of just assigning from a static
> variable:
> 
> > +             *cookie = get_random_u32() | 1;
> 
> Open-coding -EPERM?
> 
> > +     if (nxpwifi_deinit_priv_params(priv))
> > +             return -1;
> 
> Using -EFAULT for FW errors seems like a really bad idea:
> 
> > +     if (nxpwifi_drv_get_data_rate(priv, &rate)) {
> > +             nxpwifi_dbg(priv->adapter, ERROR,
> > +                         "getting data rate error\n");
> > +             return -EFAULT;
> 
> 
> But I really just scrolled through this briefly, this wasn't a real review. I don't
> know who could do a real review, but as is, it looks like someone _should_.
> 
> Johannes

Enhancement of nxpwifi based on your comments is ongoing.

Thanks,
David