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SubjectRe: [PATCH v9 12/16] serial: amba-pl011: Pass FIQ information to KGDB.
On 18/08/14 19:30, Peter Hurley wrote:
> Hi Daniel,
>
> On 08/18/2014 10:28 AM, Daniel Thompson wrote:
>> Speculatively register a FIQ resource with KGDB. KGDB will only
>> accept it if the kgdb/fiq feature is enabled (both with compile time and
>> runtime switches) and the interrupt controller supports FIQ.
>>
>> By providing this information to KGDB the serial driver offers
>> "permission" for KGDB to route the UART interrupt signal from the
>> drivers own handler to KGDBs FIQ handler (which will eventually use the
>> UART's polled I/O callbacks to interact with the user). This permission
>> also implies the amba-pl011 driver has already unmasked RX interrupts
>> (otherwise the FIQ handler will never trigger).
>>
>> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
>> Cc: Russell King <linux@arm.linux.org.uk>
>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Cc: Jiri Slaby <jslaby@suse.cz>
>> Cc: linux-serial@vger.kernel.org
>> ---
>> drivers/tty/serial/amba-pl011.c | 94 ++++++++++++++++++++++++-----------------
>> 1 file changed, 55 insertions(+), 39 deletions(-)#

Thanks for the review.


>> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
>> index 8572f2a..ec8ddc7 100644
>> --- a/drivers/tty/serial/amba-pl011.c
>> +++ b/drivers/tty/serial/amba-pl011.c
>> @@ -58,6 +58,7 @@
>> #include <linux/pinctrl/consumer.h>
>> #include <linux/sizes.h>
>> #include <linux/io.h>
>> +#include <linux/kgdb.h>
>>
>> #define UART_NR 14
>>
>> @@ -1416,8 +1417,61 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
>> spin_unlock_irqrestore(&uap->port.lock, flags);
>> }
>>
>
> Is pl011_hwinit() just being relocated in source to avoid the forward
> declaration? If so, this is usually split into its own commit.

Ok. I'll do this.


>> +static int pl011_hwinit(struct uart_port *port)
>> +{
>> + struct uart_amba_port *uap = (struct uart_amba_port *)port;
>> + int retval;
>> +
>> + /* Optionaly enable pins to be muxed in and configured */
>> + pinctrl_pm_select_default_state(port->dev);
>> +
>> + /*
>> + * Try to enable the clock producer.
>> + */
>> + retval = clk_prepare_enable(uap->clk);
>> + if (retval)
>> + return retval;
>> +
>> + uap->port.uartclk = clk_get_rate(uap->clk);
>> +
>> + /* Clear pending error and receive interrupts */
>> + writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS |
>> + UART011_RTIS | UART011_RXIS, uap->port.membase + UART011_ICR);
>> +
>> + /*
>> + * Save interrupts enable mask, and enable RX interrupts in case if
>> + * the interrupt is used for NMI entry.
>> + */
>> + uap->im = readw(uap->port.membase + UART011_IMSC);
>> + writew(UART011_RTIM | UART011_RXIM, uap->port.membase + UART011_IMSC);
>> +
>> + if (dev_get_platdata(uap->port.dev)) {
>> + struct amba_pl011_data *plat;
>> +
>> + plat = dev_get_platdata(uap->port.dev);
>> + if (plat->init)
>> + plat->init();
>> + }
>> + return 0;
>> +}
>> +
>> #ifdef CONFIG_CONSOLE_POLL
>>
>> +static int pl011_poll_init(struct uart_port *port)
>> +{
>> + struct uart_amba_port *uap = (struct uart_amba_port *)port;
>
> Please use container_of() in new code.

Ok.

Personally I dislike a file that mixes casts and conatiner_of but I
guess I can make both of us happy by switching the whole driver to
container_of. Separate patch again?


>> + int retval;
>> +
>> + retval = pl011_hwinit(port);
>> +
>> +#ifdef CONFIG_KGDB_FIQ
>> + if (retval == 0)
>> + kgdb_register_fiq(uap->port.irq);
>
> The uap->port dereference is unnecessary since the port parameter
> is the same thing.
>
> kgdb_register_fiq(port->irq);

Ok.



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