Re: [PATCH v4 3/3] media: iris: Add Gen2 firmware autodetect and fallback

[Dmitry Baryshkov]

On Fri, May 08, 2026 at 12:34:04AM +0530, Vikash Garodia wrote:
> On 4/29/2026 5:39 PM, Dikshita Agarwal wrote:
> > Some Iris platforms support both Gen1 and Gen2 HFI firmware images.
> > Update the firmware loading logic to handle this generically by
> > preferring Gen2 when available, while safely falling back to Gen1
> > when required.
> > 
> > The firmware loading logic is updated with the following priority:
> > 1. Device Tree (`firmware-name`): If specified, load unconditionally.
> > 2. Gen2 default : If no DT override exists, select the Gen2 firmware
> >     descriptor when present and attempt to load the corresponding
> >     firmware image.
> > 3. Gen1 Fallback: If loading the Gen2 firmware fails and a Gen1
> >     descriptor is available, retry with the Gen1 firmware image.
> > 
> > When a platform provides both Gen1 and Gen2 firmware descriptors and the
> > firmware is loaded via a DT override, the driver detects the
> > firmware generation at runtime before authentication by inspecting
> > the firmware data. The firmware is classified as Gen2 if the
> > QC_IMAGE_VERSION_STRING starts with "vfw" or matches the
> > "video-firmware.N.M" format with N >= 2.
> > 
> > If a Gen1 firmware image is detected in this case, the driver switches
> > to the Gen1 firmware descriptor and associated platform data so that
> > the correct HFI implementation is used.
> > 
> > This change makes firmware generation detection platform‑agnostic,
> > preserves DT overrides, prefers newer Gen2 firmware when available,
> > and maintains compatibility with platforms that only support Gen1.
> > 
> > Co-developed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Dikshita Agarwal <dikshita.agarwal@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/media/platform/qcom/iris/iris_firmware.c   | 105 +++++++++++++++++----
> >   .../platform/qcom/iris/iris_platform_common.h      |   6 +-
> >   .../media/platform/qcom/iris/iris_platform_vpu2.c  |  11 ++-
> >   .../media/platform/qcom/iris/iris_platform_vpu3x.c |   8 +-
> >   drivers/media/platform/qcom/iris/iris_probe.c      |   4 -
> >   drivers/media/platform/qcom/iris/iris_vidc.c       |   3 +
> >   6 files changed, 105 insertions(+), 32 deletions(-)
> > 
> > diff --git a/drivers/media/platform/qcom/iris/iris_firmware.c b/drivers/media/platform/qcom/iris/iris_firmware.c
> > index 1a476146d7580849d7b68c7c15dd7f82f89a680b..64a2170bf538a6d291b3d909f5563408a3a75e50 100644
> > --- a/drivers/media/platform/qcom/iris/iris_firmware.c
> > +++ b/drivers/media/platform/qcom/iris/iris_firmware.c
> > @@ -16,20 +16,95 @@
> >   #define MAX_FIRMWARE_NAME_SIZE	128
> > -static int iris_load_fw_to_memory(struct iris_core *core, const char *fw_name)
> > +/* Detect Gen2 firmware by scanning the blob for:
> > + *   QC_IMAGE_VERSION_STRING=<version>
> > + * and then checking:
> > + *   - version starts with "vfw", OR
> > + *   - version matches "video-firmware.N.M" with N >= 2
> > + */
> > +
> > +static bool iris_detect_gen2_from_fwdata(const u8 *data, size_t size)
> > +{
> > +	const char *marker = "QC_IMAGE_VERSION_STRING=";
> > +	const size_t mlen = strlen(marker);
> > +	int major = 0, minor = 0;
> > +	char version_buf[64];
> > +	size_t max;
> > +
> > +	max = (size > mlen) ? size - mlen : 0;
> 
> better to limit the size of the blob to be parsed to 4K ? version strings
> should be in the initial part of the firmware image.
> 
> A bad (and big enough) firmware blob might slow down the system with the
> current logic
> 
> something like
> size = min(size, (size_t)SZ_4K);

And if you've checked the actual firmware, you'd have seen that the
version strings can't be a part of the first 4k of it. The actual
offsets (and file sizes) for existing files in linux-firmware:

venus-1.8/venus.mbn	856876   992976
venus-4.2/venus.mbn	846796   925432
venus-5.2/venus.mbn	812224   883264
venus-5.4/venus.mbn	846904   922312
venus-6.0/venus.mbn	1159212  1794924
ar50lt_p1_gen2_s6.mbn	1167572  1861732
vpu20_p1_gen2_s6.mbn	1193056  2030620
vpu20_p1.mbn:		1188900  2026452
vpu20_p4.mbn:		1178644  1980084
vpu20_p4_sm8450_s7.mbn	1199172  2024040
vpu30_p4_s6_16mb.mbn	1356852  2315172
vpu30_p4_s6.mbn		1356852  2315156
vpu30_p4_s7.mbn		1357204  2323048
vpu33_p4_s7.mbn		1345968  2343624
vpu35_p4_s7.mbn		1339952  2409160
vpu36_p4_s7.mbn		1364016  2503368
vpu40_p2_s7.mbn		1350400  2474696

I don't think we can easily limit file area to scan for the version
string.


-- 
With best wishes
Dmitry