Re: [PATCH OLK-6.6] serial: amba-pl011: Fix serial port discard interrupt when interrupt signal line of serial port is connected to mbigen.

标题太长了； 另外这种不是很容易通过dts 新加一个属性来规避问题，为啥要加cmdline。。。

On 2023/12/14 15:42, Yuan Can wrote:

ascend inclusion category: bugfix Bugzilla: https://gitee.com/openeuler/kernel/issues/I8NC0E CVE: N/A

---

Hisi when designing ascend chip, connect the serial port interrupt signal lines to mbigen equipment, mbigen write GICD_SETSPI_NSR register trigger the SPI interrupt. This can result in serial port drop interrupts.

Signed-off-by: Xu Qiang xuqiang36@huawei.com Signed-off-by: Yuan Can yuancan@huawei.com

---

drivers/tty/serial/Kconfig | 15 +++++++++++++++ drivers/tty/serial/amba-pl011.c | 17 +++++++++++++++++ 2 files changed, 32 insertions(+)

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index bdc568a4ab66..a2577253f774 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -73,6 +73,21 @@ config SERIAL_AMBA_PL011_CONSOLE your boot loader (lilo or loadlin) about how to pass options to the kernel at boot time.)

+config SERIAL_ATTACHED_MBIGEN

• bool "Serial port interrupt signal lines connected to the mbigen"
• depends on SERIAL_AMBA_PL011=y
• depends on ASCEND_FEATURES
• default n
• help

•  Say Y here when the interrupt signal line of the serial port is
  

•  connected to the mbigne. The mbigen device has the function of
  

•  clearing interrupts automatically. However, the interrupt processing
  

•  function of the serial port driver may process multiple interrupts
  

•  at a time. The mbigen device cannot adapt to this scenario.
  

•  As a result, interrupts are lost.Because it maybe discard interrupt.
  

•  If unsure, say N.
  

• config SERIAL_EARLYCON_SEMIHOST bool "Early console using Arm compatible semihosting" depends on ARM64 || ARM || RISCV

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 3dc9b0fcab1c..713e3ef8738f 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1548,6 +1548,18 @@ static void check_apply_cts_event_workaround(struct uart_amba_port *uap) pl011_read(uap, REG_ICR); }

+#ifdef CONFIG_SERIAL_ATTACHED_MBIGEN +static bool pl011_enable_hisi_wkrd; +static int __init pl011_check_hisi_workaround_setup(char *str) +{

• pl011_enable_hisi_wkrd = 1;
• return 0;

+} +__setup("pl011_hisi_wkrd", pl011_check_hisi_workaround_setup); +#else +#define pl011_enable_hisi_wkrd 0 +#endif

• static irqreturn_t pl011_int(int irq, void *dev_id) { struct uart_amba_port *uap = dev_id;

@@ -1585,6 +1597,11 @@ static irqreturn_t pl011_int(int irq, void *dev_id) handled = 1; }

• if (pl011_enable_hisi_wkrd) {

• pl011_write(0, uap, REG_IMSC);
  

• pl011_write(uap->im, uap, REG_IMSC);
  

• }

• spin_unlock_irqrestore(&uap->port.lock, flags);

  return IRQ_RETVAL(handled);