Re: [PATCH 7/9] dev-serial: add support for setting data_bits in QEMUSerialSetParams

[Samuel Thibault]

Mark Cave-Ayland, le lun. 26 oct. 2020 08:33:59 +0000, a ecrit:
> Also implement the behaviour reported in Linux's ftdi_sio.c whereby if an 
> invalid
> data_bits value is provided then the hardware defaults to using 8.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

> ---
>  hw/usb/dev-serial.c | 17 +++++++++++++++++
>  hw/usb/trace-events |  1 +
>  2 files changed, 18 insertions(+)
> 
> diff --git a/hw/usb/dev-serial.c b/hw/usb/dev-serial.c
> index 919e25e1d9..4c374d0790 100644
> --- a/hw/usb/dev-serial.c
> +++ b/hw/usb/dev-serial.c
> @@ -308,6 +308,23 @@ static void usb_serial_handle_control(USBDevice *dev, 
> USBPacket *p,
>          break;
>      }
>      case VendorDeviceOutRequest | FTDI_SET_DATA:
> +        switch (value & 0xff) {
> +        case 7:
> +            s->params.data_bits = 7;
> +            break;
> +        case 8:
> +            s->params.data_bits = 8;
> +            break;
> +        default:
> +            /*
> +             * According to a comment in Linux's ftdi_sio.c original FTDI
> +             * chips fall back to 8 data bits for unsupported data_bits
> +             */
> +            trace_usb_serial_unsupported_data_bits(bus->busnr, dev->addr,
> +                                                   value & 0xff);
> +            s->params.data_bits = 8;
> +        }
> +
>          switch (value & FTDI_PARITY) {
>          case 0:
>              s->params.parity = 'N';
> diff --git a/hw/usb/trace-events b/hw/usb/trace-events
> index 9e984b2e0c..0d0a3e5f2a 100644
> --- a/hw/usb/trace-events
> +++ b/hw/usb/trace-events
> @@ -327,6 +327,7 @@ usb_serial_handle_control(int bus, int addr, int request, 
> int value) "dev %d:%d
>  usb_serial_unsupported_parity(int bus, int addr, int value) "dev %d:%d 
> unsupported parity %d"
>  usb_serial_unsupported_stopbits(int bus, int addr, int value) "dev %d:%d 
> unsupported stop bits %d"
>  usb_serial_unsupported_control(int bus, int addr, int request, int value) 
> "dev %d:%d got unsupported/bogus control 0x%x, value 0x%x"
> +usb_serial_unsupported_data_bits(int bus, int addr, int value) "dev %d:%d 
> unsupported data bits %d, falling back to 8"
>  usb_serial_bad_token(int bus, int addr) "dev %d:%d bad token"
>  usb_serial_set_baud(int bus, int addr, int baud) "dev %d:%d baud rate %d"
>  usb_serial_set_data(int bus, int addr, int parity, int data, int stop) "dev 
> %d:%d parity %c, data bits %d, stop bits %d"
> -- 
> 2.20.1
> 

-- 
Samuel
 > Il [e2fsck] a bien démarré, mais il m'a rendu la main aussitot en me
 > disant "houlala, c'est pas beau à voir votre truc, je préfèrerai que
 > vous teniez vous même la tronçonneuse" (traduction libre)
 NC in Guide du linuxien pervers : "Bien configurer sa tronçonneuse."