Re: [PATCH 7/8] drm/bridge: it66121: Add another implementation for getting match data

[Dmitry Baryshkov]

On Tue, 14 Nov 2023 at 17:09, Sui Jingfeng <sui.jingfeng@xxxxxxxxx> wrote:
>
> From: Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
>
> Because if use the i2c_get_match_data() function on our platform, the
> following error will emerge.
>
> [    3.597872] ACPI: bus type drm_connector registered
> [    3.602877] loongson 0000:00:06.1: Found LS7A1000 bridge chipset, revision: 1
> [    3.610013] loongson 0000:00:06.1: [drm] dc: 264MHz, gmc: 529MHz, gpu: 529MHz
> [    3.617111] loongson 0000:00:06.1: [drm] Dedicated vram start: 0xe0030000000, size: 64MiB
> [    3.633628] loongson 0000:00:06.1: [drm] Loongson VBIOS version: 0.3
> [    3.639944] loongson 0000:00:06.1: [drm] Loongson VBIOS: has 8 DCBs
> [    3.646271] Console: switching to colour dummy device 80x25
> [    3.651902] loongson 0000:00:06.1: [drm] VRAM: 4096 pages ready
> [    3.657791] loongson 0000:00:06.1: [drm] GTT: 32768 pages ready
> [    3.663731] loongson 0000:00:06.1: [drm] lsdc-i2c0(sda pin mask=1, scl pin mask=2) created
> [    3.671966] loongson 0000:00:06.1: [drm] lsdc-i2c1(sda pin mask=4, scl pin mask=8) created
> [    3.680188] loongson 0000:00:06.1: [drm] DisplayPipe-0 has DVO-0 connector
> [    3.711860] debugfs: Directory '1-004c' with parent 'regmap' already present!
> [    3.720312] CPU 0 Unable to handle kernel paging request at virtual address 0000000000000090, era == 9000000002faffec, ra == 9000000002faffc8
> [    3.732935] Oops[#1]:
> [    3.735187] CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.0-rc3+ #941
> [    3.741757] Hardware name: Loongson Loongson-3A5000-7A1000-1w-ML5A/Loongson-LS3A5000-7A1000-1w-ML5A, BIOS vUDK2018-LoongArch-V4.0.05-test-stable202305 06/
> [    3.755500] Workqueue: events work_for_cpu_fn
> [    3.759833] pc 9000000002faffec ra 9000000002faffc8 tp 900000010017c000 sp 900000010017fb80
> [    3.768132] a0 0000000000000000 a1 9000000101c00420 a2 0000000000000001 a3 900000010017fbc0
> [    3.776430] a4 0000000000000004 a5 0000000000000000 a6 0000000000000001 a7 0000000000000001
> [    3.784727] t0 0000000000000000 t1 0000000000000001 t2 0000000006124954 t3 0000000000000012
> [    3.793026] t4 0000000000004954 t5 900000000800b530 t6 0000000000000000 t7 0000000000018500
> [    3.801324] t8 90000001019c90c0 u0 9000000101c00c00 s9 fffffffffffff000 s0 9000000101c00400
> [    3.809621] s1 0000000000000000 s2 0000000000000000 s3 9000000003c42cb0 s4 9000000101c00420
> [    3.817920] s5 900000010017fc48 s6 0000000000000000 s7 0000000000000000 s8 90000000037fa000
> [    3.826219]    ra: 9000000002faffc8 i2c_get_match_data+0x24/0xac
> [    3.832189]   ERA: 9000000002faffec i2c_get_match_data+0x48/0xac
> [    3.838156]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
> [    3.844303]  PRMD: 00000004 (PPLV0 +PIE -PWE)
> [    3.848631]  EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
> [    3.853391]  ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
> [    3.858149] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
> [    3.863599]  BADV: 0000000000000090
> [    3.867058]  PRID: 0014c011 (Loongson-64bit, Loongson-3A5000)
> [    3.872764] Modules linked in:
> [    3.875793] Process kworker/0:0 (pid: 8, threadinfo=(____ptrval____), task=(____ptrval____))
> [    3.884180] Stack : 9000000101c00400 0000000000000000 900000010177f428 9000000002ceb734
> [    3.892137]         9000000101c00404 90000000037fa000 900000010017fc60 9000000101c00400
> [    3.900093]         9000000016124954 8c326e68047d36df 0000004c037fa000 900000010017fc50
> [    3.908050]         0000000000000080 9000000003c44490 900000010017fcb0 90000001003e9ec0
> [    3.916007]         0000000000000001 900000010044f000 900000010017fc60 9000000101c00400
> [    3.923964]         90000000037fa000 9000000002cf05a8 90000001003e8000 900000010017fcb2
> [    3.931920]         000000304c17fc68 0000000000000000 000000000000004c 0000000000000000
> [    3.939877]         4031323136365449 0000000000006334 004c000000000000 0000000000000000
> [    3.947833]         0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [    3.955790]         0000000000000000 0000000000000000 9000000100449a98 8c326e68047d36df
> [    3.963746]         ...
> [    3.966170] Call Trace:
> [    3.966172] [<9000000002faffec>] i2c_get_match_data+0x48/0xac
> [    3.974304] [<9000000002ceb734>] it66121_create_bridge+0x15c/0x404

This function gets added only in patch 8, it is not broken otherwise.

I can only repeat my suggestion from the previous series: register a
proper I2C device. Don't try to overplay Linux device model.

> [    3.980446] [<9000000002cf05a8>] ls7a1000_output_init+0x228/0x248
> [    3.986503] [<9000000002cee494>] lsdc_pci_probe+0x4dc/0x5b0
> [    3.992038] [<9000000002b86b50>] local_pci_probe+0x48/0xa0
> [    3.997487] [<90000000023b5d04>] work_for_cpu_fn+0x1c/0x30
> [    4.002936] [<90000000023b7c0c>] process_one_work+0x14c/0x288
> [    4.008644] [<90000000023b8084>] worker_thread+0x33c/0x438
> [    4.014092] [<90000000023c1ccc>] kthread+0x124/0x130
> [    4.019023] [<9000000002381188>] ret_from_kernel_thread+0xc/0xa4
> [    4.024991]
> [    4.026463] Code: 26000079  02c08063  4c000020 <28c24318> 43ffe31f  43ffdeff  2a00030c  43ffd59f  02c012f7
> [    4.036154]
> [    4.037630] ---[ end trace 0000000000000000 ]---
>
> Signed-off-by: Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/bridge/ite-it66121.c | 51 +++++++++++++++++++---------
>  1 file changed, 35 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
> index 2f7f00f1bedb..8971414a2a60 100644
> --- a/drivers/gpu/drm/bridge/ite-it66121.c
> +++ b/drivers/gpu/drm/bridge/ite-it66121.c
> @@ -292,8 +292,39 @@ enum chip_id {
>  struct it66121_chip_info {
>         enum chip_id id;
>         u16 vid, pid;
> +       char name[24];
>  };
>
> +static const struct it66121_chip_info it66121_chip_info[] = {
> +       {
> +               .id = ID_IT66121,
> +               .vid = 0x4954,
> +               .pid = 0x0612,
> +               .name = "IT66121",
> +       },
> +       {
> +               .id = ID_IT6610,
> +               .vid = 0xca00,
> +               .pid = 0x0611,
> +               .name = "IT6610",
> +       },
> +};
> +
> +static const struct it66121_chip_info *
> +it66121_get_match_data(u16 vender_id, u16 device_id)
> +{
> +       const struct it66121_chip_info *info;
> +       unsigned int i;
> +
> +       for (i = 0; i < ARRAY_SIZE(it66121_chip_info); i++) {
> +               info = &it66121_chip_info[i];
> +               if (info->vid == vender_id && info->pid == device_id)
> +                       return info;
> +       }
> +
> +       return NULL;
> +}
> +
>  struct it66121_ctx {
>         struct regmap *regmap;
>         struct drm_bridge bridge;
> @@ -1677,28 +1708,16 @@ static void it66121_remove(struct i2c_client *client)
>         mutex_destroy(&ctx->lock);
>  }
>
> -static const struct it66121_chip_info it66121_chip_info = {
> -       .id = ID_IT66121,
> -       .vid = 0x4954,
> -       .pid = 0x0612,
> -};
> -
> -static const struct it66121_chip_info it6610_chip_info = {
> -       .id = ID_IT6610,
> -       .vid = 0xca00,
> -       .pid = 0x0611,
> -};
> -
>  static const struct of_device_id it66121_dt_match[] = {
> -       { .compatible = "ite,it66121", &it66121_chip_info },
> -       { .compatible = "ite,it6610", &it6610_chip_info },
> +       { .compatible = "ite,it66121", &it66121_chip_info[0] },
> +       { .compatible = "ite,it6610", &it66121_chip_info[1] },
>         { }
>  };
>  MODULE_DEVICE_TABLE(of, it66121_dt_match);
>
>  static const struct i2c_device_id it66121_id[] = {
> -       { "it66121", (kernel_ulong_t) &it66121_chip_info },
> -       { "it6610", (kernel_ulong_t) &it6610_chip_info },
> +       { "it66121", (kernel_ulong_t) &it66121_chip_info[0] },
> +       { "it6610", (kernel_ulong_t) &it66121_chip_info[1] },
>         { }
>  };
>  MODULE_DEVICE_TABLE(i2c, it66121_id);
> --
> 2.34.1
>


-- 
With best wishes
Dmitry