On Tue, 20 Feb 2024, Radhakrishna Sripada <radhakrishna.sripada@xxxxxxxxx> wrote:
> oprom_get_vbt will later be used to show the contents of vbt for which
> the size of vbt is needed.
>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_bios.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index fe52c06271ef..ceb6e4145c62 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -3008,38 +3008,39 @@ static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *i915)
> return NULL;
> }
>
> -static struct vbt_header *oprom_get_vbt(struct drm_i915_private *i915)
> +static struct vbt_header *oprom_get_vbt(struct drm_i915_private *i915,
> + size_t *size)
> {
> struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> void __iomem *p = NULL, *oprom;
> struct vbt_header *vbt;
> u16 vbt_size;
> - size_t i, size;
> + size_t i;
>
> - oprom = pci_map_rom(pdev, &size);
> + oprom = pci_map_rom(pdev, size);
> if (!oprom)
> return NULL;
>
> /* Scour memory looking for the VBT signature. */
> - for (i = 0; i + 4 < size; i += 4) {
> + for (i = 0; i + 4 < *size; i += 4) {
Not a fan of using *size everywhere. Please just use size here, and do
something like this near the end:
if (sizep)
*sizep = size;
This also allows you to pass NULL when you don't need the size, like
intel_bios_init(), and you can drop the extra dummy local variable.
BR,
Jani.
> if (ioread32(oprom + i) != *((const u32 *)"$VBT"))
> continue;
>
> p = oprom + i;
> - size -= i;
> + *size -= i;
> break;
> }
>
> if (!p)
> goto err_unmap_oprom;
>
> - if (sizeof(struct vbt_header) > size) {
> + if (sizeof(struct vbt_header) > *size) {
> drm_dbg(&i915->drm, "VBT header incomplete\n");
> goto err_unmap_oprom;
> }
>
> vbt_size = ioread16(p + offsetof(struct vbt_header, vbt_size));
> - if (vbt_size > size) {
> + if (vbt_size > *size) {
> drm_dbg(&i915->drm,
> "VBT incomplete (vbt_size overflows)\n");
> goto err_unmap_oprom;
> @@ -3082,6 +3083,7 @@ void intel_bios_init(struct drm_i915_private *i915)
> const struct vbt_header *vbt;
> struct vbt_header *oprom_vbt = NULL;
> const struct bdb_header *bdb;
> + size_t size;
>
> INIT_LIST_HEAD(&i915->display.vbt.display_devices);
> INIT_LIST_HEAD(&i915->display.vbt.bdb_blocks);
> @@ -3106,7 +3108,7 @@ void intel_bios_init(struct drm_i915_private *i915)
> }
>
> if (!vbt) {
> - oprom_vbt = oprom_get_vbt(i915);
> + oprom_vbt = oprom_get_vbt(i915, &size);
> vbt = oprom_vbt;
> }
--
Jani Nikula, Intel
