Re: [PATCH] bcma: fix incorrect update of BCMA_CORE_PCI_MDIO_DATA
From: RafaÅ MiÅecki
Date: Sun Aug 25 2019 - 15:59:15 EST
On Thu, 22 Aug 2019 at 18:11, Colin Ian King <colin.king@xxxxxxxxxxxxx> wrote:
> On 22/08/2019 17:03, Larry Finger wrote:
> > On 8/22/19 8:35 AM, Colin King wrote:
> >> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >> An earlier commit re-worked the setting of the bitmask and is now
> >> assigning v with some bit flags rather than bitwise or-ing them
> >> into v, consequently the earlier bit-settings of v are being lost.
> >> Fix this by replacing an assignment with the bitwise or instead.
> >> Addresses-Coverity: ("Unused value")
> >> Fixes: 2be25cac8402 ("bcma: add constants for PCI and use them")
> >> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >> ---
> >> drivers/bcma/driver_pci.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >> diff --git a/drivers/bcma/driver_pci.c b/drivers/bcma/driver_pci.c
> >> index f499a469e66d..d219ee947c07 100644
> >> --- a/drivers/bcma/driver_pci.c
> >> +++ b/drivers/bcma/driver_pci.c
> >> @@ -78,7 +78,7 @@ static u16 bcma_pcie_mdio_read(struct bcma_drv_pci
> >> *pc, u16 device, u8 address)
> >> v |= (address << BCMA_CORE_PCI_MDIODATA_REGADDR_SHF_OLD);
> >> }
> >> - v = BCMA_CORE_PCI_MDIODATA_START;
> >> + v |= BCMA_CORE_PCI_MDIODATA_START;
> >> v |= BCMA_CORE_PCI_MDIODATA_READ;
> >> v |= BCMA_CORE_PCI_MDIODATA_TA;
> > I'm not sure the "Fixes" attribute is correct.
> > The changes for this section in commit 2be25cac8402 are
> > - v = (1 << 30); /* Start of Transaction */
> > - v |= (1 << 28); /* Write Transaction */
> > - v |= (1 << 17); /* Turnaround */
> > - v |= (0x1F << 18);
> > + v = BCMA_CORE_PCI_MDIODATA_START;
> > + v |= BCMA_CORE_PCI_MDIODATA_WRITE;
> > + v |= (BCMA_CORE_PCI_MDIODATA_DEV_ADDR <<
> > + BCMA_CORE_PCI_MDIODATA_DEVADDR_SHF);
> > + v |= (BCMA_CORE_PCI_MDIODATA_BLK_ADDR <<
> > + BCMA_CORE_PCI_MDIODATA_REGADDR_SHF);
> > + v |= BCMA_CORE_PCI_MDIODATA_TA;
> > Because the code has done quite a bit of work on v just above this
> > section, I agree that this is likely an error, but that error happened
> > in an earlier commit. Thus 2be25cac8402 did not introduce the error,
> > merely copied it.
> Ugh, this goes back further. I didn't spot that. I'm less confident of
> what the correct settings should be now.
> > Has this change been tested?
> Afraid not, I don't have the H/W.
Please send V2 with updated commit message (Fixes tag) +
bcma_pcie_mdio_write fixed. I'll try to test it.