Hi Thomas,
On Fri Jun 20, 2025 at 1:02 PM CEST, Thomas Zimmermann wrote:
> Hi
>
> Am 20.06.25 um 12:31 schrieb Luca Weiss:
>> Some devices might require keeping an interconnect path alive so that
>> the framebuffer continues working. Add support for that by setting the
>> bandwidth requirements appropriately for all provided interconnect
>> paths.
>>
>> Signed-off-by: Luca Weiss <luca.we...@fairphone.com>
>> ---
>> drivers/video/fbdev/simplefb.c | 83
>> ++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 83 insertions(+)
>>
>> diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c
>> index
>> be95fcddce4c8ca794826b805cd7dad2985bd637..ca73e079fd13550ddc779e84db80f7f9b743d074
>> 100644
>> --- a/drivers/video/fbdev/simplefb.c
>> +++ b/drivers/video/fbdev/simplefb.c
>> @@ -27,6 +27,7 @@
>> #include <linux/parser.h>
>> #include <linux/pm_domain.h>
>> #include <linux/regulator/consumer.h>
>> +#include <linux/interconnect.h>
>
> With alphabetical sorting:
>
> Reviewed-by: Thomas Zimmermann <tzimmerm...@suse.de>
Thanks for the reviews!
For both simpledrm.c and simplefb.c, the includes are not strictly
alphabetically sorted (1 mis-sort in simpledrm, 3 in simplefb), shall I
just try and slot it into the best fitting place, or make them sorted in
my patch? Or I can add a separate commit for each driver before to sort
them.
Let me know!
Regards
Luca
>
> Best regards
> Thomas
>
>
>>
>> static const struct fb_fix_screeninfo simplefb_fix = {
>> .id = "simple",
>> @@ -89,6 +90,10 @@ struct simplefb_par {
>> u32 regulator_count;
>> struct regulator **regulators;
>> #endif
>> +#if defined CONFIG_OF && defined CONFIG_INTERCONNECT
>> + unsigned int icc_count;
>> + struct icc_path **icc_paths;
>> +#endif
>> };
>>
>> static void simplefb_clocks_destroy(struct simplefb_par *par);
>> @@ -525,6 +530,80 @@ static int simplefb_attach_genpds(struct simplefb_par
>> *par,
>> }
>> #endif
>>
>> +#if defined CONFIG_OF && defined CONFIG_PM_GENERIC_DOMAINS
>> +/*
>> + * Generic interconnect path handling code.
>> + */
>> +static void simplefb_detach_icc(void *res)
>> +{
>> + struct simplefb_par *par = res;
>> + int i;
>> +
>> + for (i = par->icc_count - 1; i >= 0; i--) {
>> + if (!IS_ERR_OR_NULL(par->icc_paths[i]))
>> + icc_put(par->icc_paths[i]);
>> + }
>> +}
>> +
>> +static int simplefb_attach_icc(struct simplefb_par *par,
>> + struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + int ret, count, i;
>> +
>> + count = of_count_phandle_with_args(dev->of_node, "interconnects",
>> + "#interconnect-cells");
>> + if (count < 0)
>> + return 0;
>> +
>> + /* An interconnect path consists of two elements */
>> + if (count % 2) {
>> + dev_err(dev, "invalid interconnects value\n");
>> + return -EINVAL;
>> + }
>> + par->icc_count = count / 2;
>> +
>> + par->icc_paths = devm_kcalloc(dev, par->icc_count,
>> + sizeof(*par->icc_paths),
>> + GFP_KERNEL);
>> + if (!par->icc_paths)
>> + return -ENOMEM;
>> +
>> + for (i = 0; i < par->icc_count; i++) {
>> + par->icc_paths[i] = of_icc_get_by_index(dev, i);
>> + if (IS_ERR_OR_NULL(par->icc_paths[i])) {
>> + ret = PTR_ERR(par->icc_paths[i]);
>> + if (ret == -EPROBE_DEFER)
>> + goto err;
>> + dev_err(dev, "failed to get interconnect path %u:
>> %d\n", i, ret);
>> + continue;
>> + }
>> +
>> + ret = icc_set_bw(par->icc_paths[i], 0, UINT_MAX);
>> + if (ret) {
>> + dev_err(dev, "failed to set interconnect bandwidth %u:
>> %d\n", i, ret);
>> + continue;
>> + }
>> + }
>> +
>> + return devm_add_action_or_reset(dev, simplefb_detach_icc, par);
>> +
>> +err:
>> + while (i) {
>> + --i;
>> + if (!IS_ERR_OR_NULL(par->icc_paths[i]))
>> + icc_put(par->icc_paths[i]);
>> + }
>> + return ret;
>> +}
>> +#else
>> +static int simplefb_attach_icc(struct simplefb_par *par,
>> + struct platform_device *pdev)
>> +{
>> + return 0;
>> +}
>> +#endif
>> +
>> static int simplefb_probe(struct platform_device *pdev)
>> {
>> int ret;
>> @@ -615,6 +694,10 @@ static int simplefb_probe(struct platform_device *pdev)
>> if (ret < 0)
>> goto error_regulators;
>>
>> + ret = simplefb_attach_icc(par, pdev);
>> + if (ret < 0)
>> + goto error_regulators;
>> +
>> simplefb_clocks_enable(par, pdev);
>> simplefb_regulators_enable(par, pdev);
>>
>>
