Re: [PATCH] misc: cardreader: fix overwritten return value in RTS5260 driver

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Jul 27, 2025 at 04:41:34PM -0700, Tian wrote:
> In both rts5260.c and rtsx_pcr.c, a return value is set and then
> overwritten by a later function call, which makes the original value
> unused. This patch ensures the return value is handled properly
> to avoid ignoring possible error conditions.
> 
> Signed-off-by: Tian <27392025k@gmail.com>

Please use your ful name as per the kernel documentation.

> ---
>  drivers/misc/cardreader/rts5260.c  | 2 +-
>  drivers/misc/cardreader/rtsx_pcr.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/misc/cardreader/rts5260.c b/drivers/misc/cardreader/rts5260.c
> index d2d3a6ccb8f7..ed8adaab54a8 100644
> --- a/drivers/misc/cardreader/rts5260.c
> +++ b/drivers/misc/cardreader/rts5260.c
> @@ -269,7 +269,7 @@ static int rts5260_card_power_off(struct rtsx_pcr *pcr, int card)
>  	rts5260_card_before_power_off(pcr);
>  	err = rtsx_pci_write_register(pcr, LDO_VCC_CFG1,
>  			 LDO_POW_SDVDD1_MASK, LDO_POW_SDVDD1_OFF);
> -	err = rtsx_pci_write_register(pcr, LDO_CONFIG2,
> +	err |= rtsx_pci_write_register(pcr, LDO_CONFIG2,
>  			 DV331812_POWERON, DV331812_POWEROFF);

How was this tested?

And why do the second write if the first one failed?


>  	if (pcr->option.ocp_en)
>  		rtsx_pci_disable_ocp(pcr);

Why do this if the write failed?

> diff --git a/drivers/misc/cardreader/rtsx_pcr.c b/drivers/misc/cardreader/rtsx_pcr.c
> index a7b066c48740..9fb22f2cedbd 100644
> --- a/drivers/misc/cardreader/rtsx_pcr.c
> +++ b/drivers/misc/cardreader/rtsx_pcr.c
> @@ -1196,7 +1196,7 @@ static int rtsx_pci_init_hw(struct rtsx_pcr *pcr)
>  		/* Gating real mcu clock */
>  		err = rtsx_pci_write_register(pcr, RTS5261_FW_CFG1,
>  			RTS5261_MCU_CLOCK_GATING, 0);
> -		err = rtsx_pci_write_register(pcr, RTS5261_REG_FPDCTL,
> +		err |= rtsx_pci_write_register(pcr, RTS5261_REG_FPDCTL,
>  			SSC_POWER_DOWN, 0);

Is this even going to ever happen?  Same for above, how was this tested?

thanks,

greg k-h