On Tue, Jan 03, 2023 at 10:00:48AM +0100, Jiri Slaby wrote: > On 26. 12. 22, 7:21, Deepak R Varma wrote: > > The refcount_* APIs are designed to address known issues with the > > atomic_t APIs for reference counting. They provide following distinct > > advantages: > > - protect the reference counters from overflow/underflow > > - avoid use-after-free errors > > - provide improved memory ordering guarantee schemes > > - neater and safer. > > Hence, replace the atomic_* APIs by their equivalent refcount_t > > API functions. > > > > This patch proposal address the following warnings generated by > > the atomic_as_refcounter.cocci coccinelle script > > atomic_add_return(-1, ...) > ... > > --- a/drivers/tty/serial/dz.c > > +++ b/drivers/tty/serial/dz.c > ... > > @@ -400,18 +399,16 @@ static int dz_startup(struct uart_port *uport) > > struct dz_port *dport = to_dport(uport); > > struct dz_mux *mux = dport->mux; > > unsigned long flags; > > - int irq_guard; > > int ret; > > u16 tmp; > > > > - irq_guard = atomic_add_return(1, &mux->irq_guard); > > - if (irq_guard != 1) > > + refcount_inc(&mux->irq_guard); > > + if (refcount_read(&mux->irq_guard) != 1) > > return 0; > > > > - ret = request_irq(dport->port.irq, dz_interrupt, > > - IRQF_SHARED, "dz", mux); > > + ret = request_irq(dport->port.irq, dz_interrupt, IRQF_SHARED, "dz", mux); > > How is this related to the above described change? No, it is not. My apologies. I must have joined the lines for improved readability and forgot to revert. I will restore this in next revision based on the feedback on the other patch of this series. OR I can include this change in the current change log as a "while at it..." statement. Would you advise me? Thank you, ./drv > > -- > js > suse labs >
