Re: [EXT] Re: [PATCH v5 2/2] misc: nxp-sr1xx: UWB driver support for sr1xx series chip

[Manjunatha Venkatesh]

On 10/7/2022 7:41 PM, Arnd Bergmann wrote:
> Caution: EXT Email
>
> On Fri, Oct 7, 2022, at 4:04 PM, Manjunatha Venkatesh wrote:
> > sr1xx_dev_open(struct inode *inode, struct file *filp)
> > > > +{
> > > > +     struct sr1xx_dev *sr1xx_dev =
> > > > +         container_of(filp->private_data, struct sr1xx_dev, sr1xx_device);
> > > > +
> > > > +     filp->private_data = sr1xx_dev;
> > > This looks dangerous if the file gets opened more than once
> > > and filp->private_data can have two different values.
> > Do you suggest us to use mutex lock inside open api?
>
> > > > +
> > > > +     sr1xx_dev->spi = spi;
> > > > +     sr1xx_dev->sr1xx_device.minor = MISC_DYNAMIC_MINOR;
> > > > +     sr1xx_dev->sr1xx_device.name = "sr1xx";
> > > > +     sr1xx_dev->sr1xx_device.fops = &sr1xx_dev_fops;
> > > > +     sr1xx_dev->sr1xx_device.parent = &spi->dev;
> > > > +     sr1xx_dev->irq_gpio = desc_to_gpio(platform_data.gpiod_irq);
> > > > +     sr1xx_dev->ce_gpio = desc_to_gpio(platform_data.gpiod_ce);
> > > > +     sr1xx_dev->spi_handshake_gpio =
> > > > +         desc_to_gpio(platform_data.gpiod_spi_handshake);
> > > The temporary 'platform_data' structure seems useless here,
> > > just fold its members into the sr1xx_dev structure itself.
> > > No need to store both a gpio descriptor and a number, you
> > > can simplify this to always use the descriptor.
> > Just to keep separate function(sr1xx_hw_setup) for better readability
> > we have added intermediate platform_data structure.
> I'm fairly sure it adds nothing to readability if every reader has
> to wonder about why you have a platform_data structure here when
> the device was never used without devicetree.
Will fix this in the next patch submission.
> > > > +     sr1xx_dev->tx_buffer = kzalloc(SR1XX_TXBUF_SIZE, GFP_KERNEL);
> > > > +     sr1xx_dev->rx_buffer = kzalloc(SR1XX_RXBUF_SIZE, GFP_KERNEL);
> > > > +     if (!sr1xx_dev->tx_buffer) {
> > > > +             ret = -ENOMEM;
> > > > +             goto err_exit;
> > > > +     }
> > > > +     if (!sr1xx_dev->rx_buffer) {
> > > > +             ret = -ENOMEM;
> > > > +             goto err_exit;
> > > > +     }
> > > > +
> > > > +     sr1xx_dev->spi->irq = gpio_to_irq(sr1xx_dev->irq_gpio);
> > > > +     if (sr1xx_dev->spi->irq < 0) {
> > > > +             dev_err(&spi->dev, "gpio_to_irq request failed gpio = 0x%x\n",
> > > > +                     sr1xx_dev->irq_gpio);
> > > > +             goto err_exit;
> > > > +     }
> > > Instead of gpio_to_irq(), the DT binding should probably
> > > list the interrupt directly using the "interrupts" property
> > > pointing to the gpio controller. Since, we are configured this as generic GPIO in DT binding. So, we
> > are using gpio_to_irq() to use as IRQ pin.
> I meant you should change the binding first, and then adapt the
> code to match. Remove all references to gpio numbers from
> the code.
Will work on this suggestion and update in the next patch submission.
>      Arnd