Re: [RFC PATCH 1/6] spi: Extend the core to ease integration of SPI memory controllers

Boris Brezillon
2018-02-28T12:26:36Z

On Wed, 28 Feb 2018 15:51:29 +0800
Peter Pan <peterpansjtu@gmail.com> wrote:

> > +int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> > +{
> > + unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
> > + struct spi_controller *ctlr = mem->spi->controller;
> > + struct spi_transfer xfers[4] = { };
> > + struct spi_message msg;
> > + u8 *tmpbuf;
> > + int ret;
> > +
> > + if (!spi_mem_supports_op(mem, op))
> > + return -ENOTSUPP;
> > +
> > + if (ctlr->mem_ops) {
> > + if (ctlr->auto_runtime_pm) {
> > + ret = pm_runtime_get_sync(ctlr->dev.parent);
> > + if (ret < 0) {
> > + dev_err(&ctlr->dev,
> > + "Failed to power device: %d\n",
> > + ret);
> > + return ret;
> > + }
> > + }
> > +
> > + mutex_lock(&ctlr->bus_lock_mutex);
> > + mutex_lock(&ctlr->io_mutex);
> > + ret = ctlr->mem_ops->exec_op(mem, op);
> > + mutex_unlock(&ctlr->io_mutex);
> > + mutex_unlock(&ctlr->bus_lock_mutex);
> > +
> > + if (ctlr->auto_runtime_pm)
> > + pm_runtime_put(ctlr->dev.parent);
> > +
> > + /*
> > + * Some controllers only optimize specific paths (typically the
> > + * read path) and expect the core to use the regular SPI
> > + * interface in these cases.
> > + */
> > + if (!ret || ret != -ENOTSUPP)
> > + return ret;
> > + }
> > +
> > + tmpbufsize = sizeof(op->cmd.opcode) + op->addr.nbytes +
> > + op->dummy.nbytes;
>
> Here you are using sizeof(op->cmd.opcode) while the code after this
> assumes opcode is u8(ie. "memcpy(tmpbuf + 1, op->addr.buf, op->addr.nbytes);")
> It may be confused.

Will use sizeof(op->cmd.opcode) everywhere then.

--
Boris Brezillon, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering