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    SubjectRe: [PATCH v3 2/4] Watchdog: sp5100_tco: Refactor MMIO base address initialization
    On Tue, Jan 18, 2022 at 10:23 PM Terry Bowman <terry.bowman@amd.com> wrote:
    >
    > Combine MMIO base address and alternate base address detection. Combine
    > based on layout type. This will simplify the function by eliminating
    > a switch case.
    >
    > Move existing request/release code into functions. This currently only
    > supports port I/O request/release. The move into a separate function
    > will make it ready for adding MMIO region support.

    ...

    > To: Guenter Roeck <linux@roeck-us.net>
    > To: linux-watchdog@vger.kernel.org
    > To: Jean Delvare <jdelvare@suse.com>
    > To: linux-i2c@vger.kernel.org
    > To: Wolfram Sang <wsa@kernel.org>
    > To: Andy Shevchenko <andy.shevchenko@gmail.com>
    > To: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
    > Cc: linux-kernel@vger.kernel.org
    > Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
    > Cc: Robert Richter <rrichter@amd.com>
    > Cc: Thomas Lendacky <thomas.lendacky@amd.com>

    Same comment to all your patches.

    ...

    > +static int __sp5100_tco_prepare_base(struct sp5100_tco *tco,
    > + u32 mmio_addr,
    > + const char *dev_name)
    > +{
    > + struct device *dev = tco->wdd.parent;

    > + int ret = 0;

    Not really used variable.

    > + if (!mmio_addr)
    > + return -ENOMEM;
    > +
    > + if (!devm_request_mem_region(dev, mmio_addr,
    > + SP5100_WDT_MEM_MAP_SIZE,
    > + dev_name)) {
    > + dev_dbg(dev, "MMIO address 0x%08x already in use\n",
    > + mmio_addr);
    > + return -EBUSY;
    > + }
    > +
    > + tco->tcobase = devm_ioremap(dev, mmio_addr,
    > + SP5100_WDT_MEM_MAP_SIZE);
    > + if (!tco->tcobase) {
    > + dev_dbg(dev, "MMIO address 0x%08x failed mapping.\n",
    > + mmio_addr);

    > + devm_release_mem_region(dev, mmio_addr,
    > + SP5100_WDT_MEM_MAP_SIZE);

    Why? If it's a short live mapping, do not use devm.

    > + return -ENOMEM;
    > + }

    > + dev_info(dev, "Using 0x%08x for watchdog MMIO address\n",
    > + mmio_addr);

    Unneeded noise.

    > + return ret;

    On top of above it's a NIH devm_ioremap_resource().

    > +}


    ...

    > + int ret = 0;

    Redundant assignment.

    ...

    > + /* Check MMIO address conflict */
    > + ret = __sp5100_tco_prepare_base(tco, mmio_addr, dev_name);

    > +
    > + /* Check alternate MMIO address conflict */

    Unify this with the previous comment.

    > + if (ret)
    > + ret = __sp5100_tco_prepare_base(tco, alt_mmio_addr,
    > + dev_name);

    ...

    > + if (alt_mmio_addr & ((SB800_ACPI_MMIO_DECODE_EN |
    > + SB800_ACPI_MMIO_SEL) !=
    > + SB800_ACPI_MMIO_DECODE_EN)) {

    The split looks ugly. Consider to use temporary variables or somehow
    rearrange the condition that it doesn't break in the middle of the one
    logical token.

    > + alt_mmio_addr &= ~0xFFF;

    Why capital letters?

    > + alt_mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
    > + }

    ...

    > + if (!(alt_mmio_addr & (((SB800_ACPI_MMIO_DECODE_EN |
    > + SB800_ACPI_MMIO_SEL)) !=
    > + SB800_ACPI_MMIO_DECODE_EN))) {

    Ditto.

    > + alt_mmio_addr &= ~0xFFF;

    Ditto.

    > + alt_mmio_addr += SB800_PM_WDT_MMIO_OFFSET;

    ...

    Okay, I see this is the original code like this... Perhaps it makes
    sense to reshuffle them (indentation-wise) at the same time and
    mention this in the changelog.

    ...

    > release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);

    Is it still needed? I have no context to say if devm_iomap() and this
    are not colliding, please double check the correctness.

    --
    With Best Regards,
    Andy Shevchenko

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