Hello Andy, On Tue, Apr 16, 2024 at 05:59:59PM +0300, Andy Shevchenko wrote: > On Tue, Apr 16, 2024 at 11:52:19AM +0200, Uwe Kleine-König wrote: > > On Mon, Apr 15, 2024 at 10:04:39PM +0200, Uwe Kleine-König wrote: > > > On Mon, Apr 15, 2024 at 10:36:44PM +0300, Andy Shevchenko wrote: > > > > On Mon, Apr 15, 2024 at 07:15:54PM +0200, Uwe Kleine-König wrote: > > ... > > > > > You might need this > > > > > > > > 1aa4ad4eb695 serial: core: Fix missing shutdown and startup for serial base port > > > > > > > > on top btw. > > > > > > Ah, that looks exactly like my issue. Thanks, I will test that an report > > > back. > > > > It improves my situation for sure. I have yet another problem with the > > stm32 UART that is driver specfic. I'm working on that one now ... > > Please, Cc me on that when publishing, I'm curious. I don't have a fix yet, but the problem reproduces as follows: I have a bridge between TX and RX; and also between RTS and CTS; there is no DMA involved. I send a big amount of data and so receive that all. This puts pressure on the receiving line discipline and so ->throttle() is called. ->throttle() sets stm32_port->throttled = true; which makes the ISR (= stm32_usart_interrupt()) stop handle USART_SR_RXNE (= RXFIFO not empty). So the ISR is called in a tight loop. Stuck irq detection doesn't step in because the ISR returns IRQ_HANDLED unconditionally. (For the latter I already have a prototype patch.) It's unclear to me yet, what to do. Some further things that are (maybe) relevant are: - Without a rts-gpio the driver cannot toggle RTS. (Hardware limitation) - The driver makes no effort evaluating CTS. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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