Re: [PATCH i-g-t v3 04/10] lib/intel_device_info: add a helper to guess the PCI ID for a codename

[Jani Nikula <jani.nikula@intel.com>]

On Mon, 15 Jun 2026, Michał Grzelak <michal.grzelak@intel.com> wrote:
> From: Jani Nikula <jani.nikula@intel.com>
>
> From: Jani Nikula <jani.nikula@intel.com>
>

Where did the dupe From: come from?

Anyway, would be more helpful to get the original patches merged than
include them here, especially since there were review comments on them.

> The struct intel_device_info contains the codenames for the
> corresponding PCI device IDs. Add a reverse lookup to get a PCI ID for a
> codename.
>
> It's a bit fuzzy, though. The codenames aren't always spelled the same,
> there are suffixes sometimes omitted, and you can only pick one of the
> matching PCI IDs. Name the helper intel_guess_device_id() to emphasize
> the point, and try increasing fuzziness in the matching to find an
> appropriate struct intel_device_info.
>
> There's nothing exact about this, and it should not be considered as
> such. But it will be useful in VBT parsing.
>
> Cc: Michał Grzelak <michal.grzelak@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

You *must* add your own Signed-off-by when sending someone else's
patches. See [1] for what Signed-off-by means.

BR,
Jani.


[1] https://developercertificate.org/


> ---
>  lib/intel_chipset.h     |  1 +
>  lib/intel_device_info.c | 75 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 76 insertions(+)
>
> diff --git a/lib/intel_chipset.h b/lib/intel_chipset.h
> index 3fcc5b18d6..98a2a81fcf 100644
> --- a/lib/intel_chipset.h
> +++ b/lib/intel_chipset.h
> @@ -103,6 +103,7 @@ struct intel_device_info {
>  };
>  
>  const struct intel_device_info *intel_get_device_info(uint16_t devid) __attribute__((pure));
> +uint16_t intel_guess_device_id(const char *codenameish) __attribute__((pure));
>  
>  const struct intel_cmds_info *intel_get_cmds_info(uint16_t devid) __attribute__((pure));
>  unsigned intel_gen(uint16_t devid) __attribute__((pure));
> diff --git a/lib/intel_device_info.c b/lib/intel_device_info.c
> index da0b9f3988..3b53732650 100644
> --- a/lib/intel_device_info.c
> +++ b/lib/intel_device_info.c
> @@ -3,6 +3,7 @@
>  #include "i915_pciids_local.h"
>  
>  #include <strings.h> /* ffs() */
> +#include <ctype.h>
>  
>  static const struct intel_device_info intel_generic_info = {
>  	.graphics_ver = 0,
> @@ -746,6 +747,80 @@ out:
>  	return cache;
>  }
>  
> +static bool char_eq(char c1, char c2)
> +{
> +	c1 = isalnum(c1) ? tolower(c1) : '-';
> +	c2 = isalnum(c2) ? tolower(c2) : '-';
> +
> +	return c1 == c2;
> +}
> +
> +/*
> + * Return true if the codenames s1 and s2 match, with fuzziness.
> + *
> + * Case insensitive matching, ignoring differences in non-alnum characters. With
> + * non-zero fuzziness, accept matches up to the first non-alnum character.
> + */
> +static bool codename_match(const char *s1, const char *s2, int fuzziness)
> +{
> +	while (*s1 && *s2 && char_eq(*s1, *s2)) {
> +		s1++;
> +		s2++;
> +	}
> +
> +	/* full match */
> +	if (!*s1 && !*s2)
> +		return true;
> +
> +	/* sub-string match up to a non-alnum char */
> +	if (fuzziness >=1) {
> +		if (!*s1 && !isalnum(*s2))
> +			return true;
> +		if (!*s2 && !isalnum(*s1))
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
> +static uint16_t lookup_device_id(const char *codename, int fuzziness)
> +{
> +	int i;
> +
> +	for (i = 0; intel_device_match[i].device_id != PCI_MATCH_ANY; i++) {
> +		const struct intel_device_info *info = (void *)intel_device_match[i].match_data;
> +
> +		if (codename_match(info->codename, codename, fuzziness))
> +			return intel_device_match[i].device_id;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * intel_guess_device_id:
> + * @codenameish: something resembling a codename
> + *
> + * Based on something resembling a codename, try to fuzzy find the first PCI
> + * device ID matching the codename.
> + *
> + * Returns:
> + * PCI device ID fuzzy matching the @codenameish, or 0 if no match was found.
> + */
> +uint16_t intel_guess_device_id(const char *codenameish)
> +{
> +	uint16_t devid;
> +	int fuzziness;
> +
> +	for (fuzziness = 0; fuzziness < 2; fuzziness++) {
> +		devid = lookup_device_id(codenameish, fuzziness);
> +		if (devid)
> +			return devid;
> +	}
> +
> +	return 0;
> +}
> +
>  /**
>   * intel_get_cmds_info:
>   * @devid: pci device id

-- 
Jani Nikula, Intel