On Thu, Aug 29, 2024 at 05:15:42PM +0800, Jiawen Wu wrote:
> On Fri, Aug 23, 2024 10:13 PM, Andy Shevchenko wrote:
> > On Fri, Aug 23, 2024 at 11:02:42AM +0800, Jiawen Wu wrote:
...
> > > +static int i2c_dw_txgbe_acquire_lock(struct dw_i2c_dev *dev)
> > > +{
> > > + void __iomem *req_addr;
> > > + u32 swsm;
> > > + int i;
> > > +
> > > + req_addr = dev->ext + I2C_DW_TXGBE_MNG_SW;
> > > +
> > > + for (i = 0; i < I2C_DW_TXGBE_REQ_RETRY_CNT; i++) {
> >
> > Retry loops much better in a form of
> >
> > unsigned int retries = ...;
> > ...
> > do {
> > ...
> > } while (--retries);
> >
> > BUT... see below.
> >
> > > + writel(I2C_DW_TXGBE_MNG_SW_SM, req_addr);
> > > +
> > > + /* If we set the bit successfully then we got semaphore. */
> > > + swsm = readl(req_addr);
> > > + if (swsm & I2C_DW_TXGBE_MNG_SW_SM)
> > > + break;
> > > +
> > > + udelay(50);
> >
> > So, can a macro from iopoll.h be utilised here? Why not?
>
> I need to write the register first and then read it in this loop.
> It does not seem to apply to the macros in iopoll.h.
I don't see how does it prevent from using read_poll_timeout() macro.
You need to implement a body of the loop as a helper function that you supply
into macro as a parameter.
> > > + }
> > > +
> > > + if (i == I2C_DW_TXGBE_REQ_RETRY_CNT)
> > > + return -ETIMEDOUT;
> > > +
> > > + return 0;
> > > +}
--
With Best Regards,
Andy Shevchenko
