On Fri, Oct 23, 2020 at 07:00:43PM -0700, Hemant Kumar wrote:
> It is possible that the device does not support the number of event
> rings and channels that the controller would like to use. Read the
> MHICFG to determine device-side support and if the controller requests
> more than the device supports, bailout without configuring device MMIO
> registers.
>
> Signed-off-by: Hemant Kumar
> ---
> drivers/bus/mhi/core/init.c | 31 +++
> drivers/bus/mhi/core/internal.h | 4
> 2 files changed, 35 insertions(+)
>
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 70fd6af..35a6b1d 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -488,6 +488,37 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
> { 0, 0, 0 }
> };
>
> + /* range check b/w host and device supported ev rings and channels */
> + ret = mhi_read_reg(mhi_cntrl, base, MHICFG, &val);
> + if (ret) {
> + dev_err(dev, "Unable to read MHICFG register\n");
> + return -EIO;
> + }
> +
> + if (MHICFG_NHWER(val) < mhi_cntrl->hw_ev_rings) {
> + dev_err(dev, "#HWEV ring: host requires %d dev supports %d\n",
> + mhi_cntrl->hw_ev_rings, MHICFG_NHWER(val));
Can you please improve this error message? Something like, "Host
requires %d hw event rings but dev supports only %d".
Do this for below errors as well. With that,
Reviewed-by: Manivannan Sadhasivam
Thanks,
Mani
> + return -EIO;
> + }
> +
> + if (MHICFG_NER(val) < mhi_cntrl->total_ev_rings) {
> + dev_err(dev, "#EV ring: host requires %d dev supports %d\n",
> + mhi_cntrl->total_ev_rings, MHICFG_NER(val));
> + return -EIO;
> + }
> +
> + if (MHICFG_NHWCH(val) < mhi_cntrl->hw_chan) {
> + dev_err(dev, "#HWCH: host requires %d dev supports %d\n",
> + mhi_cntrl->hw_chan, MHICFG_NHWCH(val));
> + return -EIO;
> + }
> +
> + if (MHICFG_NCH(val) < mhi_cntrl->max_chan) {
> + dev_err(dev, "#CH: host requires %d dev supports %d\n",
> + mhi_cntrl->max_chan, MHICFG_NCH(val));
> + return -EIO;
> + }
> +
> dev_dbg(dev, "Initializing MHI registers\n");
>
> /* Read channel db offset */
> diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
> index 3d8e480..9cbfa71 100644
> --- a/drivers/bus/mhi/core/internal.h
> +++ b/drivers/bus/mhi/core/internal.h
> @@ -28,6 +28,10 @@ extern struct bus_type mhi_bus_type;
> #define MHICFG_NHWCH_SHIFT (8)
> #define MHICFG_NCH_MASK (0xFF)
> #define MHICFG_NCH_SHIFT (0)
> +#define MHICFG_NHWER(n) (((n) & MHICFG_NHWER_MASK) >> MHICFG_NHWER_SHIFT)
> +#define MHICFG_NER(n) (((n) & MHICFG_NER_MASK) >> MHICFG_NER_SHIFT)
> +#define MHICFG_NHWCH(n) (((n) & MHICFG_NHWCH_MASK) >> MHICFG_NHWCH_SHIFT)
> +#define MHICFG_NCH(n) (((n) & MHICFG_NCH_MASK) >> MHICFG_NCH_SHIFT)
>
> #define CHDBOFF (0x18)
> #define CHDBOFF_CHDBOFF_MASK (0x)
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
