Hi Mark,
On 1/27/22 20:03, Mark Pearson wrote:
> Lenovo AMD based platforms have been offering platform_profiles but they
> are not working correctly. This is because the mode we are using on the
> Intel platforms (MMC) is not available on the AMD platforms.
>
> This commit adds checking of the functional capabilities returned by the
> BIOS to confirm if MMC is supported or not. Profiles will not be
> available if the platform is not MMC capable.
>
> I'm investigating and working on an alternative for AMD platforms but
> that is still work-in-progress.
>
> Signed-off-by: Mark Pearson <markpearson@xxxxxxxxxx>
> ---
> Changes in v2:
> - Rebased on review-hans branch to be in sync with latest
> - Return -ENODEV if funtion not available
>
> drivers/platform/x86/thinkpad_acpi.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
> index 33f611af6e51..5e4de74586cd 100644
> --- a/drivers/platform/x86/thinkpad_acpi.c
> +++ b/drivers/platform/x86/thinkpad_acpi.c
> @@ -10119,6 +10119,9 @@ static struct ibm_struct proxsensor_driver_data = {
> #define DYTC_CMD_MMC_GET 8 /* To get current MMC function and mode */
> #define DYTC_CMD_RESET 0x1ff /* To reset back to default */
>
> +#define DYTC_CMD_FUNC_CAP 3 /* To get DYTC capabilities */
> +#define DYTC_FC_MMC 27 /* MMC Mode supported */
> +
> #define DYTC_GET_FUNCTION_BIT 8 /* Bits 8-11 - function setting */
> #define DYTC_GET_MODE_BIT 12 /* Bits 12-15 - mode setting */
>
> @@ -10331,6 +10334,15 @@ static int tpacpi_dytc_profile_init(struct ibm_init_struct *iibm)
> if (dytc_version < 5)
> return -ENODEV;
>
> + /* Check what capabilities are supported. Currently MMC is needed */
> + err = dytc_command(DYTC_CMD_FUNC_CAP, &output);
> + if (err)
> + return err;
> + if (!test_bit(DYTC_FC_MMC, (void *)&output)) {
Erm test_bit operates on longs, so it may read an entire long from
&output which is 64 bits on x86_64, thus exceeding the space allocated
on the stack by 32 bits.
To avoid this I've replaced the if with:
if (!(output & BIT(DYTC_FC_MMC))) {
And verified on a x1c8 that the performance-profiles still work there
after this change.
Thank you for your patch, I've applied this patch to my review-hans
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans
I will include this patch in the upcoming pdx86 fixes for 5.17
pull-req which I will send out soon.
Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.
Regards,
Hans
> + dbg_printk(TPACPI_DBG_INIT, " DYTC MMC mode not supported\n");
> + return -ENODEV;
> + }
> +
> dbg_printk(TPACPI_DBG_INIT,
> "DYTC version %d: thermal mode available\n", dytc_version);
> /*
>
