From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jingoo Han <jg1.han@samsung.com>
Subject: Re: [PATCH 3/8] [SCSI] dc395x: use NULL instead of 0
Date: Wed, 07 Aug 2013 17:36:32 +0900
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To: 'Julian Calaby' <julian.calaby@gmail.com>
Cc: 'Oliver Neukum' <oliver@neukum.org>, 'James Bottomley' <JBottomley@parallels.com>, 'Ali Akcaagac' <aliakc@web.de>, 'Jamie Lenehan' <lenehan@twibble.org>, dc395x@twibble.org, 'James Bottomley' <jejb@kernel.org>, 'linux-scsi' <linux-scsi@vger.kernel.org>, Jingoo Han <jg1.han@samsung.com>



> -----Original Message-----
> From: Julian Calaby [mailto:julian.calaby@gmail.com]
> Sent: Wednesday, August 07, 2013 5:21 PM
> To: Jingoo Han
> Cc: Oliver Neukum; James Bottomley; Ali Akcaagac; Jamie Lenehan; dc395x@twibble.org; James Bottomley;
> linux-scsi
> Subject: Re: [PATCH 3/8] [SCSI] dc395x: use NULL instead of 0
> 
> Hi Jingoo,
> 
> On Wed, Aug 7, 2013 at 5:45 PM, Jingoo Han <jg1.han@samsung.com> wrote:
> > On Wednesday, August 07, 2013 3:50 PM, Oliver Neukum wrote:
> >> On Wed, 2013-08-07 at 12:55 +0900, Jingoo Han wrote:
> >>
> >> > @@ -4183,15 +4183,17 @@ static void check_eeprom(struct NvRamType *eeprom, unsigned long io_port)
> >> >              */
> >> >             dprintkl(KERN_WARNING,
> >> >                     "EEProm checksum error: using default values and options.\n");
> >> > -           eeprom->sub_vendor_id[0] = (u8)PCI_VENDOR_ID_TEKRAM;
> >> > +           eeprom->sub_vendor_id[0] = (u8)(PCI_VENDOR_ID_TEKRAM & 0xff);
> >>
> >> Hi,
> >>
> >> if you are fixing these issues please use the proper macros for
> >> conversion of endianness.
> >
> > Then, do you mean the following? :)
> >
> > -       prom->sub_vendor_id[0] = (u8)PCI_VENDOR_ID_TEKRAM;
> > +       eprom->sub_vendor_id[0] = (u8)(PCI_VENDOR_ID_TEKRAM & le16_to_cpu(0xff));
> 
> No.
> 
> The issue is that the driver is doing things like this:
> 
> eeprom->member[0] = (u8)(CONSTANT & 0xff);
> eeprom->member[1] = (u8)(CONSTANT >> 8);
> 
> Which is exactly the same as code along the lines of:
> 
> eeprom->member = cpu_to_le16(CONSTANT);

However, when I compile the following, it makes build error.

-               eeprom->sub_vendor_id[0] = (u8)(PCI_VENDOR_ID_TEKRAM & 0xff);
-               eeprom->sub_vendor_id[1] = (u8)(PCI_VENDOR_ID_TEKRAM >> 8);
+               eeprom->sub_vendor_id = cpu_to_le16(PCI_VENDOR_ID_TEKRAM);

Best regards,
Jingoo Han