On Mon, Jun 12, 2017 at 01:47:58PM -0400, Jérémy Lefaure wrote: > In i5000 and i5400 edac drivers, the register nrecmemb is defined as a > 16 bits value which result in wrong shifts in the code: > CHECK drivers/edac/i5000_edac.c > drivers/edac/i5000_edac.c:485:15: warning: right shift by bigger than > source value > drivers/edac/i5000_edac.c:580:23: warning: right shift by bigger than > source value > CC drivers/edac/i5000_edac.o > CHECK drivers/edac/i5400_edac.c > drivers/edac/i5400_edac.c:391:36: warning: right shift by bigger than > source value > drivers/edac/i5400_edac.c:401:37: warning: right shift by bigger than > source value > CC drivers/edac/i5400_edac.o > > In the datasheets ([1], section 3.9.22.20 and [2], section 3.9.22.21), > this register is a 32 bits register. A u32 value for the register fixes > the wrong shifts warnings and matches the datasheet. > > This patch also fixes the mask to access to the CAS bits [16 to 28] in > the i5000 edac driver. > > [1]: > https://www.intel.com/content/dam/doc/datasheet/5000p-5000v-5000z-chipset-memory-controller-hub-datasheet.pdf
Well, the CAS field length here is [27:16], see below. > [2]: > https://www.intel.se/content/dam/doc/datasheet/5400-chipset-memory-controller-hub-datasheet.pdf Here it is [28:16]. > Signed-off-by: Jérémy Lefaure <[email protected]> > --- > > I have found this error thanks to the sparse tool. Please note that this patch > hasn't been tested on real hardware. > > > drivers/edac/i5000_edac.c | 6 +++--- > drivers/edac/i5400_edac.c | 4 ++-- > 2 files changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/edac/i5000_edac.c b/drivers/edac/i5000_edac.c > index f683919981b0..c79016ade51e 100644 > --- a/drivers/edac/i5000_edac.c > +++ b/drivers/edac/i5000_edac.c > @@ -227,7 +227,7 @@ > #define NREC_RDWR(x) (((x)>>11) & 1) > #define NREC_RANK(x) (((x)>>8) & 0x7) > #define NRECMEMB 0xC0 > -#define NREC_CAS(x) (((x)>>16) & 0xFFFFFF) > +#define NREC_CAS(x) (((x)>>16) & 0x1FFF) That is still incorrect. According to the 5000? datasheet above, NRECMEMB has the CAS field in bits [27:16]. That's 12 bits, so the mask should be 0xFFF. IOW, #define NREC_CAS(x) (((x)>>16) & 0xFFF) The 0x1FFF mask is correct for the 5400 driver because the CAS field there is [28:16]. The fact that no one caught this by now goes to show how many people are actually using this thing. :-\ -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.
