RE: [Patch V8 2/3] tpm_tis-spi: Add hardware wait polling

[Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx>]

> -----Original Message-----
> From: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> Sent: 19 March 2023 19:13
> To: Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx>
> Cc: robh+dt@xxxxxxxxxx; broonie@xxxxxxxxxx; peterhuewe@xxxxxx;
> jgg@xxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx; linux-spi@xxxxxxxxxxxxxxx;
> linux-tegra@xxxxxxxxxxxxxxx; linux-integrity@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; thierry.reding@xxxxxxxxx; Jonathan Hunter
> <jonathanh@xxxxxxxxxx>; Sowjanya Komatineni
> <skomatineni@xxxxxxxxxx>; Laxman Dewangan <ldewangan@xxxxxxxxxx>
> Subject: Re: [Patch V8 2/3] tpm_tis-spi: Add hardware wait polling
> 
> External email: Use caution opening links or attachments
> 
> 
> On Wed, Mar 15, 2023 at 03:47:33PM +0000, Krishna Yarlagadda wrote:
> >
> > > -----Original Message-----
> > > From: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> > > Sent: 12 March 2023 03:19
> > > To: Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx>; robh+dt@xxxxxxxxxx;
> > > broonie@xxxxxxxxxx; peterhuewe@xxxxxx; jgg@xxxxxxxx;
> > > krzysztof.kozlowski+dt@xxxxxxxxxx; linux-spi@xxxxxxxxxxxxxxx; linux-
> > > tegra@xxxxxxxxxxxxxxx; linux-integrity@xxxxxxxxxxxxxxx; linux-
> > > kernel@xxxxxxxxxxxxxxx
> > > Cc: thierry.reding@xxxxxxxxx; Jonathan Hunter
> <jonathanh@xxxxxxxxxx>;
> > > Sowjanya Komatineni <skomatineni@xxxxxxxxxx>; Laxman Dewangan
> > > <ldewangan@xxxxxxxxxx>
> > > Subject: Re: [Patch V8 2/3] tpm_tis-spi: Add hardware wait polling
> > >
> > > External email: Use caution opening links or attachments
> > >
> > >
> > > On Thu, 2023-03-02 at 09:48 +0530, Krishna Yarlagadda wrote:
> > > > +int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16
> > > > len,
> > > > +                        u8 *in, const u8 *out)
> > > > +{
> > > > +       struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
> > > > +       struct spi_controller *ctlr = phy->spi_device->controller;
> > > > +
> > > > +       /*
> > > > +        * TPM flow control over SPI requires full duplex support.
> > > > +        * Send entire message to a half duplex controller to handle
> > > > +        * wait polling in controller.
> > > > +        * Set TPM HW flow control flag..
> > > > +        */
> > > > +       if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
> > > > +               return tpm_tis_spi_hw_flow_transfer(data, addr, len,
> > > > in,
> > > > +                                                   out);
> > > > +       else
> > > > +               return tpm_tis_spi_sw_flow_transfer(data, addr, len,
> > > > in,
> > > > +                                                   out);
> > > > +}
> > > > +
> > >
> > > Based on the condition, better names would be
> > Though condition is based on half duplex, functions are implementing
> > HW or SW flow of the transfer.
> 
> Both are hardwaw flows in the sense that you are controlling a piece of
> hardware.
> 
> BR, Jarkko
Yes. I will push new version with naming suggested.
KY