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Date:   Thu, 20 Oct 2022 22:22:10 +0200
From:   Nam Cao <namcaov@gmail.com>
To:     Gautam Menghani <gautammenghani201@gmail.com>
Cc:     gregkh@linuxfoundation.org, paulo.miguel.almeida.rodenas@gmail.com,
        linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drivers/staging/pi433: Change data type of bit_rate to
 be u32
Message-ID: <20221020202210.GA16547@nam-dell>
References: <20221020181815.31245-1-gautammenghani201@gmail.com>
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In-Reply-To: <20221020181815.31245-1-gautammenghani201@gmail.com>
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On Thu, Oct 20, 2022 at 11:48:15PM +0530, Gautam Menghani wrote:
> A TODO asks to convert the bit_rate variable to be a u32 so that bit 
> rates up to 300kbps can be supported as per the spec.
> 
> Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
> ---
> Please note that this patch is only compile tested.
> 
>  drivers/staging/pi433/TODO       | 2 --
>  drivers/staging/pi433/pi433_if.h | 4 ++--
>  drivers/staging/pi433/rf69.c     | 2 +-
>  drivers/staging/pi433/rf69.h     | 2 +-
>  4 files changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/staging/pi433/TODO b/drivers/staging/pi433/TODO
> index 5cf3fd99d521..8530bbe61d70 100644
> --- a/drivers/staging/pi433/TODO
> +++ b/drivers/staging/pi433/TODO
> @@ -1,5 +1,3 @@
>  * currently the code introduces new IOCTLs. I'm afraid this is a bad idea.
>    -> Replace this with another interface, hints are welcome!
>  * Some missing data (marked with ###) needs to be added in the documentation
> -* Change (struct pi433_tx_cfg)->bit_rate to be a u32 so that we can support
> -    bit rates up to 300kbps per the spec.
> diff --git a/drivers/staging/pi433/pi433_if.h b/drivers/staging/pi433/pi433_if.h
> index 25ee0b77a32c..c958dcfa9f96 100644
> --- a/drivers/staging/pi433/pi433_if.h
> +++ b/drivers/staging/pi433/pi433_if.h
> @@ -51,7 +51,7 @@ enum option_on_off {
>  #define PI433_TX_CFG_IOCTL_NR	0
>  struct pi433_tx_cfg {
>  	__u32			frequency;
> -	__u16			bit_rate;
> +	__u32			bit_rate;
>  	__u32			dev_frequency;
>  	enum modulation		modulation;
>  	enum mod_shaping	mod_shaping;
> @@ -99,7 +99,7 @@ struct pi433_tx_cfg {
>  #define PI433_RX_CFG_IOCTL_NR	1
>  struct pi433_rx_cfg {
>  	__u32			frequency;
> -	__u16			bit_rate;
> +	__u32			bit_rate;
>  	__u32			dev_frequency;
>  
>  	enum modulation		modulation;
> diff --git a/drivers/staging/pi433/rf69.c b/drivers/staging/pi433/rf69.c
> index 8c7fab6a46bb..7e754a3aef5f 100644
> --- a/drivers/staging/pi433/rf69.c
> +++ b/drivers/staging/pi433/rf69.c
> @@ -185,7 +185,7 @@ int rf69_set_modulation_shaping(struct spi_device *spi,
>  	}
>  }
>  
> -int rf69_set_bit_rate(struct spi_device *spi, u16 bit_rate)
> +int rf69_set_bit_rate(struct spi_device *spi, u32 bit_rate)
>  {
>  	int retval;
>  	u32 bit_rate_reg;
> diff --git a/drivers/staging/pi433/rf69.h b/drivers/staging/pi433/rf69.h
> index 78fa0b8bab8b..46a1fb2d5329 100644
> --- a/drivers/staging/pi433/rf69.h
> +++ b/drivers/staging/pi433/rf69.h
> @@ -24,7 +24,7 @@ int rf69_set_data_mode(struct spi_device *spi, u8 data_mode);
>  int rf69_set_modulation(struct spi_device *spi, enum modulation modulation);
>  int rf69_set_modulation_shaping(struct spi_device *spi,
>  				enum mod_shaping mod_shaping);
> -int rf69_set_bit_rate(struct spi_device *spi, u16 bit_rate);
> +int rf69_set_bit_rate(struct spi_device *spi, u32 bit_rate);
>  int rf69_set_deviation(struct spi_device *spi, u32 deviation);
>  int rf69_set_frequency(struct spi_device *spi, u32 frequency);
>  int rf69_enable_amplifier(struct spi_device *spi, u8 amplifier_mask);
> -- 
> 2.34.1
>

I sent (almost) the exact same patch a while ago. I received a reply
saying that doing this is not possible. That conversation can still be
found here:
https://lore.kernel.org/linux-staging/20220315180820.7393-1-cvn249@gmail.com/t/#u

Best regards,
Nam