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    SubjectRe: [PATCH V3 2/2] serial: uartlite: Use dynamic allocation for major number when uart ports > 4
    On Thu, 16 Nov 2023 12:59:15 +0530
    Manikanta Guntupalli <manikanta.guntupalli@amd.com> wrote:

    Hi,

    > Device number 204 has a range of minors on major number.
    > uart_register_driver is failing due to lack of minor numbers
    > when more number of uart ports used. So, to avoid minor number
    > limitation on 204 major number use dynamic major allocation
    > when more than 4 uart ports used otherwise use static major
    > allocation.
    >
    > https://docs.kernel.org/arch/arm/sa1100/serial_uart.html
    >
    > Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
    > ---
    > Changes for V2:
    > Update logic to use either static or dynamic major allocation.
    > Update commit description.
    > Update description of SERIAL_UARTLITE_NR_UARTS in Kconfig.
    > Changes for V3:
    > Fix typo.
    > Remove parentheses.
    > ---
    > drivers/tty/serial/Kconfig | 2 ++
    > drivers/tty/serial/uartlite.c | 5 +++++
    > 2 files changed, 7 insertions(+)
    >
    > diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
    > index 732c893c8d16..c3c82b740078 100644
    > --- a/drivers/tty/serial/Kconfig
    > +++ b/drivers/tty/serial/Kconfig
    > @@ -532,6 +532,8 @@ config SERIAL_UARTLITE_NR_UARTS
    > help
    > Set this to the number of uartlites in your system, or the number
    > you think you might implement.
    > + If maximum number of uartlite serial ports are more than 4, then driver uses

    "are more" -> "is more"

    "then driver" -> "the driver" (or "then the driver")

    Hugo.

    > + dynamic allocation instead of static allocation for major number.
    >
    > config SERIAL_SUNCORE
    > bool
    > diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
    > index 404c14acafa5..66d751edcf45 100644
    > --- a/drivers/tty/serial/uartlite.c
    > +++ b/drivers/tty/serial/uartlite.c
    > @@ -24,8 +24,13 @@
    > #include <linux/pm_runtime.h>
    >
    > #define ULITE_NAME "ttyUL"
    > +#if CONFIG_SERIAL_UARTLITE_NR_UARTS > 4
    > +#define ULITE_MAJOR 0 /* use dynamic node allocation */
    > +#define ULITE_MINOR 0
    > +#else
    > #define ULITE_MAJOR 204
    > #define ULITE_MINOR 187
    > +#endif
    > #define ULITE_NR_UARTS CONFIG_SERIAL_UARTLITE_NR_UARTS
    >
    > /* ---------------------------------------------------------------------
    > --
    > 2.25.1
    >


    --
    Hugo Villeneuve <hugo@hugovil.com>

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