Messages in this thread | | | Subject | Re: [PATCH] bcma: fix incorrect update of BCMA_CORE_PCI_MDIO_DATA | From | Larry Finger <> | Date | Thu, 22 Aug 2019 11:38:04 -0500 |
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On 8/22/19 11:11 AM, Colin Ian King 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@canonical.com> >>> >>> 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@canonical.com> >>> --- >>> 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.
I admit that I looked at this only because I found it hard to believe that the collective wisdom of the list would have missed the usage of "=" instead of "|=". At least that test was passed. :)
Larry
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