Re: [PATCH 0/3] Handle UART without interrupt on TEMT using em485

From: Eric Tremblay
Date: Mon Feb 01 2021 - 19:04:44 EST


On 2021-01-28 7:12 p.m., Giulio Benetti wrote:
> Hi Eric,
>
>> Il giorno 29 gen 2021, alle ore 00:37, Eric Tremblay <etremblay@xxxxxxxxxxxxxxxxxxxx> ha scritto:
>>
>> The series is mainly about the support of 8250 UART without TEMT
>> interrupt. I saw that there was some development in the past but
>> it was never merged. Since the last discussion were quite some
>> time ago, I was not sure if I should post a v4 over the
>> last v3 or start from scratch so I decided to post a new patch. Please
>> advice if I should have done the reverse.
> Please keep my and Heiko’s SoB and add your SoB too describing between [ ] what Heiko has done and what you’ve done.
> For example:
> SoB: Giulio
> SoB: Heiko
> [Heiko: ...]
> SoB Eric
> [Eric: improved timeout etc.]

I will add them in the next version, thanks for mentioning it.

>
>> The approach is a little different from the last proposed patch which was
>> doing using a polling at 100us. I tought that it could be really long on
>> some fast baudrate and really not that long on slow baudrate. The current
>> approach is to calculate the time of a bytes when the settings are changed.
>> When we get the interrupt for the empty FIFO, it's the longer it can take
>> to empty the shift register.
> Good idea.
>
>> The other two patches are to use that features with the PORT_16550A_FSL64
>> found on some chip like the LS1043A.
> Do you mind to add my 8250_dw patch that was originally part of this patchset? I had to send it
> soon, you’ve preceded me :-)

I think there was still a comment pending on that patch. I think you should resubmit
since I think it's a bit out-of-scope for me.

>
> Thank you
> Best regards
> Giulio
>
>> Thanks
>>
>> Eric Tremblay (3):
>> serial: 8250: Handle UART without interrupt on TEMT using em485
>> serial: 8250: add compatible for fsl,16550-FIFO64
>> serial: 8250: remove UART_CAP_TEMT on PORT_16550A_FSL64
>>
>> drivers/tty/serial/8250/8250.h | 1 +
>> drivers/tty/serial/8250/8250_bcm2835aux.c | 2 +-
>> drivers/tty/serial/8250/8250_of.c | 5 ++
>> drivers/tty/serial/8250/8250_omap.c | 2 +-
>> drivers/tty/serial/8250/8250_port.c | 89 ++++++++++++++++++++++-
>> include/linux/serial_8250.h | 2 +
>> 6 files changed, 98 insertions(+), 3 deletions(-)
>>
>> --
>> 2.17.1