On Mon, 20 Aug 2018 13:01:13 +0000
David Laight <David.Laight@xxxxxxxxxx> wrote:
> From: Chuanhua Han
> > Sent: 20 August 2018 13:44
> >
Still no message here, and the subject prefix is still wrong.
Fixes and Cc-stable tags should be placed here...
> > Signed-off-by: Chuanhua Han <chuanhua.han@xxxxxxx>
> > ---
> > Changes in v3:
> > Rename variable name "val" to "opcode_addr_dummy_sum".
> > Place the legitimacy of the transfer size(i.e., "pi_max_message_size(mem->spi)" and
> > "opcode_addr_dummy_sum") into "if (! ctlr - > mem_ops | |! ctlr-> mem_ops->exec_op) {"
> > structure and add "spi_max_transfer_size(mem->spi) and opcode_addr_dummy_sum".
> > Adjust the formatting alignment of your code.
> > "(unsigned long)op->data.nbytes" was modified to "(unsigned long)(op->data.nbytes)".
> >
> > Fixes: c36ff266dc82 ("spi: Extend the core to ease integration of SPI memory controllers")
... not here.
The changelog should also contain a "Changes in v2" section.
> > ---
> > drivers/spi/spi-mem.c | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
> > index 990770d..5ec2bc9 100644
> > --- a/drivers/spi/spi-mem.c
> > +++ b/drivers/spi/spi-mem.c
> > @@ -328,10 +328,24 @@ EXPORT_SYMBOL_GPL(spi_mem_exec_op);
> > int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
> > {
> > struct spi_controller *ctlr = mem->spi->controller;
> > + unsigned long opcode_addr_dummy_sum = sizeof(op->cmd.opcode) +
> > + op->addr.nbytes +
> > + op->dummy.nbytes;
>
Yep, the var name is definitely too long.
> I'd split that (and shorten the variable name) to avoid line wrap. Maybe:
>
> unsigned long len;
>
> len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
> >
> > if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
> > return ctlr->mem_ops->adjust_op_size(mem, op);
> >
> > + if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
> > + if (spi_max_message_size(mem->spi) < opcode_addr_dummy_sum ||
> > + spi_max_transfer_size(mem->spi) < opcode_addr_dummy_sum)
> > + return -EINVAL;
>
> Those comparisons are lexically backwards, you want 'value op constant'.
> So:
> if (len > spi_max_message_size(mem->spi) ||
> len > spi_max_transfer_size(mem->spi))
> return -EINVAL.
> Although I'm surprised you need to do both comparisons.
Indeed, spi_max_transfer_size() is enough since it already does a min()
with spi_max_message_size().
>
> > +
> > + op->data.nbytes = min3((unsigned long)(op->data.nbytes),
Hm, you should have a cast of size_t, I guess that's what kbuild robots
reported.
> > + spi_max_transfer_size(mem->spi),
> > + spi_max_message_size(mem->spi) -
> > + opcode_addr_dummy_sum);
>
> That looks like a strange limit...
We need that to adjust the len of the 2nd transfer (called data in
spi-mem) if it's too long to fit in a SPI message or SPI transfer.
>
> > + }
> > +
> > return 0;
> > }
> > EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
> > --
> > 2.7.4
>
> David
>
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
>
