Messages in this thread | | | From | Arnd Bergmann <> | Date | Wed, 11 Jul 2018 16:19:51 +0200 | Subject | Re: [PATCH v5 07/10] i3c: master: Add driver for Cadence IP |
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On Fri, Jun 22, 2018 at 12:49 PM, Boris Brezillon <boris.brezillon@bootlin.com> wrote: > Add a driver for Cadence I3C master IP.
The driver seems very well-written and shows that the framework got that side of the interface right. Just one thing I noticed:
> + > +static void cdns_i3c_master_handle_ibi(struct cdns_i3c_master *master, > + u32 ibir)
> + > + for (i = 0; i < IBIR_XFER_BYTES(ibir); i += 4) { > + u32 tmp = readl(master->regs + IBI_DATA_FIFO); > + > + for (j = 0; j < 4 && i + j < dev->ibi->max_payload_len; j++) > + buf[i + j] = tmp >> (j * 8); > + }
This seems to be a rather inefficient way to open-code a readsl(). I suppose you need to handle length that is not a multiple of 4, right?
Maybe do it like
size_t length = IBIR_XFER_BYTES(ibir); readsl(master->regs + IBI_DATA_FIFO, buf, length & ~3); if (length & 3) { u32 tmp = __raw_readl(master->regs + IBI_DATA_FIFO); memcpy(buf + length & ~3, length & 3); }
Arnd
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