Re: [PATCH] [RFC] media: rcar-csi2: Corrects the selection of hsfreqrange

From: Niklas Söderlund
Date: Mon Mar 16 2020 - 09:02:55 EST


Hi Suresh,

Gentle ping on this. Do you plan to send a new version of this patch?

On 2020-03-04 20:46:02 +0100, Niklas Söderlund wrote:
> Hi Suresh,
>
> Thanks for your work!
>
> On 2020-02-20 13:49:09 +0900, Suresh Udipi wrote:
> > hsfreqrange should be chosen based on the calculated mbps which
> > is closer to the default bit rate and within the range as per
> > table[1]. But current calculation always selects fist value which
> > greater than the calcuated mbps which may lead to chosing a
> > wrong range in some cases.
> >
> > For example for 360 mbps for H3/M3N
> > Existing logic selects
> > Calculated value 360Mbps : Default 400Mbps Range [368.125 -433.125 mbps]
> >
> > This hsfreqrange is buggy and also out of range.
> >
> > The logic is changed to get the default value which is closest to the
> > calculated value [1]
> >
> > Calculate value 360Mbps : Default 350Mbps Range [320.625 -380.625 mpbs]
> >
> > [1] specs r19uh0105ej0200-r-car-3rd-generation.pdf [Table 25.9]
>
> It's great that you are addressing this issue. Out of curiosity what
> hardware setup and configuration have you used to trigger the issue (if
> any)?
>
> >
> > Signed-off-by: Suresh Udipi <sudipi@xxxxxxxxxxxxxx>
> > Signed-off-by: Kazuyoshi Akiyama <akiyama@xxxxxxxxxxxxx>
> > ---
> > drivers/media/platform/rcar-vin/rcar-csi2.c | 185 +++++++++++++++-------------
> > 1 file changed, 97 insertions(+), 88 deletions(-)
> >
> > diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
> > index faa9fb2..1966ece 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
> > @@ -134,6 +134,8 @@ struct phtw_value {
> > struct rcsi2_mbps_reg {
> > u16 mbps;
> > u16 reg;
> > + u16 min;
> > + u16 max;
> > };
> >
> > static const struct rcsi2_mbps_reg phtw_mbps_h3_v3h_m3n[] = {
> > @@ -201,96 +203,96 @@ static const struct rcsi2_mbps_reg phtw_mbps_v3m_e3[] = {
> > #define PHYPLL_HSFREQRANGE(n) ((n) << 16)
> >
> > static const struct rcsi2_mbps_reg hsfreqrange_h3_v3h_m3n[] = {
> > - { .mbps = 80, .reg = 0x00 },
> > - { .mbps = 90, .reg = 0x10 },
> > - { .mbps = 100, .reg = 0x20 },
> > - { .mbps = 110, .reg = 0x30 },
> > - { .mbps = 120, .reg = 0x01 },
> > - { .mbps = 130, .reg = 0x11 },
> > - { .mbps = 140, .reg = 0x21 },
> > - { .mbps = 150, .reg = 0x31 },
> > - { .mbps = 160, .reg = 0x02 },
> > - { .mbps = 170, .reg = 0x12 },
> > - { .mbps = 180, .reg = 0x22 },
> > - { .mbps = 190, .reg = 0x32 },
> > - { .mbps = 205, .reg = 0x03 },
> > - { .mbps = 220, .reg = 0x13 },
> > - { .mbps = 235, .reg = 0x23 },
> > - { .mbps = 250, .reg = 0x33 },
> > - { .mbps = 275, .reg = 0x04 },
> > - { .mbps = 300, .reg = 0x14 },
> > - { .mbps = 325, .reg = 0x25 },
> > - { .mbps = 350, .reg = 0x35 },
> > - { .mbps = 400, .reg = 0x05 },
> > - { .mbps = 450, .reg = 0x16 },
> > - { .mbps = 500, .reg = 0x26 },
> > - { .mbps = 550, .reg = 0x37 },
> > - { .mbps = 600, .reg = 0x07 },
> > - { .mbps = 650, .reg = 0x18 },
> > - { .mbps = 700, .reg = 0x28 },
> > - { .mbps = 750, .reg = 0x39 },
> > - { .mbps = 800, .reg = 0x09 },
> > - { .mbps = 850, .reg = 0x19 },
> > - { .mbps = 900, .reg = 0x29 },
> > - { .mbps = 950, .reg = 0x3a },
> > - { .mbps = 1000, .reg = 0x0a },
> > - { .mbps = 1050, .reg = 0x1a },
> > - { .mbps = 1100, .reg = 0x2a },
> > - { .mbps = 1150, .reg = 0x3b },
> > - { .mbps = 1200, .reg = 0x0b },
> > - { .mbps = 1250, .reg = 0x1b },
> > - { .mbps = 1300, .reg = 0x2b },
> > - { .mbps = 1350, .reg = 0x3c },
> > - { .mbps = 1400, .reg = 0x0c },
> > - { .mbps = 1450, .reg = 0x1c },
> > - { .mbps = 1500, .reg = 0x2c },
> > + { .mbps = 80, .reg = 0x00, .min = 80, .max = 97 },
> > + { .mbps = 90, .reg = 0x10, .min = 80, .max = 107 },
> > + { .mbps = 100, .reg = 0x20, .min = 83, .max = 118 },
> > + { .mbps = 110, .reg = 0x30, .min = 93, .max = 128 },
> > + { .mbps = 120, .reg = 0x01, .min = 103, .max = 139 },
> > + { .mbps = 130, .reg = 0x11, .min = 112, .max = 149 },
> > + { .mbps = 140, .reg = 0x21, .min = 122, .max = 160 },
> > + { .mbps = 150, .reg = 0x31, .min = 131, .max = 170 },
> > + { .mbps = 160, .reg = 0x02, .min = 141, .max = 181 },
> > + { .mbps = 170, .reg = 0x12, .min = 150, .max = 191 },
> > + { .mbps = 180, .reg = 0x22, .min = 160, .max = 202 },
> > + { .mbps = 190, .reg = 0x32, .min = 169, .max = 212 },
> > + { .mbps = 205, .reg = 0x03, .min = 183, .max = 228 },
> > + { .mbps = 220, .reg = 0x13, .min = 198, .max = 224 },
> > + { .mbps = 235, .reg = 0x23, .min = 212, .max = 259 },
> > + { .mbps = 250, .reg = 0x33, .min = 226, .max = 275 },
> > + { .mbps = 275, .reg = 0x04, .min = 250, .max = 301 },
> > + { .mbps = 300, .reg = 0x14, .min = 274, .max = 328 },
> > + { .mbps = 325, .reg = 0x25, .min = 297, .max = 354 },
> > + { .mbps = 350, .reg = 0x35, .min = 321, .max = 380 },
> > + { .mbps = 400, .reg = 0x05, .min = 369, .max = 433 },
> > + { .mbps = 450, .reg = 0x16, .min = 416, .max = 485 },
> > + { .mbps = 500, .reg = 0x26, .min = 464, .max = 538 },
> > + { .mbps = 550, .reg = 0x37, .min = 499, .max = 590 },
> > + { .mbps = 600, .reg = 0x07, .min = 559, .max = 643 },
> > + { .mbps = 650, .reg = 0x18, .min = 606, .max = 695 },
> > + { .mbps = 700, .reg = 0x28, .min = 654, .max = 748 },
> > + { .mbps = 750, .reg = 0x39, .min = 701, .max = 800 },
> > + { .mbps = 800, .reg = 0x09, .min = 749, .max = 853 },
> > + { .mbps = 850, .reg = 0x19, .min = 796, .max = 905 },
> > + { .mbps = 900, .reg = 0x29, .min = 844, .max = 958 },
> > + { .mbps = 950, .reg = 0x3a, .min = 891, .max = 1010 },
> > + { .mbps = 1000, .reg = 0x0a, .min = 939, .max = 1063 },
> > + { .mbps = 1050, .reg = 0x1a, .min = 986, .max = 1115 },
> > + { .mbps = 1100, .reg = 0x2a, .min = 1034, .max = 1168 },
> > + { .mbps = 1150, .reg = 0x3b, .min = 1081, .max = 1220 },
> > + { .mbps = 1200, .reg = 0x0b, .min = 1129, .max = 1273 },
> > + { .mbps = 1250, .reg = 0x1b, .min = 1176, .max = 1325 },
> > + { .mbps = 1300, .reg = 0x2b, .min = 1212, .max = 1378 },
> > + { .mbps = 1350, .reg = 0x3c, .min = 1271, .max = 1430 },
> > + { .mbps = 1400, .reg = 0x0c, .min = 1319, .max = 1483 },
> > + { .mbps = 1450, .reg = 0x1c, .min = 1366, .max = 1500 },
> > + { .mbps = 1500, .reg = 0x2c, .min = 1414, .max = 1500 },
> > { /* sentinel */ },
> > };
> >
> > static const struct rcsi2_mbps_reg hsfreqrange_m3w_h3es1[] = {
> > - { .mbps = 80, .reg = 0x00 },
> > - { .mbps = 90, .reg = 0x10 },
> > - { .mbps = 100, .reg = 0x20 },
> > - { .mbps = 110, .reg = 0x30 },
> > - { .mbps = 120, .reg = 0x01 },
> > - { .mbps = 130, .reg = 0x11 },
> > - { .mbps = 140, .reg = 0x21 },
> > - { .mbps = 150, .reg = 0x31 },
> > - { .mbps = 160, .reg = 0x02 },
> > - { .mbps = 170, .reg = 0x12 },
> > - { .mbps = 180, .reg = 0x22 },
> > - { .mbps = 190, .reg = 0x32 },
> > - { .mbps = 205, .reg = 0x03 },
> > - { .mbps = 220, .reg = 0x13 },
> > - { .mbps = 235, .reg = 0x23 },
> > - { .mbps = 250, .reg = 0x33 },
> > - { .mbps = 275, .reg = 0x04 },
> > - { .mbps = 300, .reg = 0x14 },
> > - { .mbps = 325, .reg = 0x05 },
> > - { .mbps = 350, .reg = 0x15 },
> > - { .mbps = 400, .reg = 0x25 },
> > - { .mbps = 450, .reg = 0x06 },
> > - { .mbps = 500, .reg = 0x16 },
> > - { .mbps = 550, .reg = 0x07 },
> > - { .mbps = 600, .reg = 0x17 },
> > - { .mbps = 650, .reg = 0x08 },
> > - { .mbps = 700, .reg = 0x18 },
> > - { .mbps = 750, .reg = 0x09 },
> > - { .mbps = 800, .reg = 0x19 },
> > - { .mbps = 850, .reg = 0x29 },
> > - { .mbps = 900, .reg = 0x39 },
> > - { .mbps = 950, .reg = 0x0a },
> > - { .mbps = 1000, .reg = 0x1a },
> > - { .mbps = 1050, .reg = 0x2a },
> > - { .mbps = 1100, .reg = 0x3a },
> > - { .mbps = 1150, .reg = 0x0b },
> > - { .mbps = 1200, .reg = 0x1b },
> > - { .mbps = 1250, .reg = 0x2b },
> > - { .mbps = 1300, .reg = 0x3b },
> > - { .mbps = 1350, .reg = 0x0c },
> > - { .mbps = 1400, .reg = 0x1c },
> > - { .mbps = 1450, .reg = 0x2c },
> > - { .mbps = 1500, .reg = 0x3c },
> > + { .mbps = 80, .reg = 0x00, .min = 80, .max = 110 },
> > + { .mbps = 90, .reg = 0x10, .min = 80, .max = 120 },
> > + { .mbps = 100, .reg = 0x20, .min = 80, .max = 131 },
> > + { .mbps = 110, .reg = 0x30, .min = 81, .max = 141 },
> > + { .mbps = 120, .reg = 0x01, .min = 91, .max = 152 },
> > + { .mbps = 130, .reg = 0x11, .min = 100, .max = 162 },
> > + { .mbps = 140, .reg = 0x21, .min = 110, .max = 173 },
> > + { .mbps = 150, .reg = 0x31, .min = 119, .max = 183 },
> > + { .mbps = 160, .reg = 0x02, .min = 129, .max = 194 },
> > + { .mbps = 170, .reg = 0x12, .min = 138, .max = 204 },
> > + { .mbps = 180, .reg = 0x22, .min = 148, .max = 215 },
> > + { .mbps = 190, .reg = 0x32, .min = 157, .max = 225 },
> > + { .mbps = 205, .reg = 0x03, .min = 171, .max = 241 },
> > + { .mbps = 220, .reg = 0x13, .min = 186, .max = 257 },
> > + { .mbps = 235, .reg = 0x23, .min = 200, .max = 273 },
> > + { .mbps = 250, .reg = 0x33, .min = 238, .max = 276 },
> > + { .mbps = 275, .reg = 0x04, .min = 250, .max = 301 },
> > + { .mbps = 300, .reg = 0x14, .min = 274, .max = 328 },
> > + { .mbps = 325, .reg = 0x05, .min = 297, .max = 354 },
> > + { .mbps = 350, .reg = 0x15, .min = 321, .max = 393 },
> > + { .mbps = 400, .reg = 0x25, .min = 357, .max = 446 },
> > + { .mbps = 450, .reg = 0x06, .min = 404, .max = 498 },
> > + { .mbps = 500, .reg = 0x16, .min = 452, .max = 551 },
> > + { .mbps = 550, .reg = 0x07, .min = 499, .max = 603 },
> > + { .mbps = 600, .reg = 0x17, .min = 547, .max = 656 },
> > + { .mbps = 650, .reg = 0x08, .min = 594, .max = 708 },
> > + { .mbps = 700, .reg = 0x18, .min = 642, .max = 761 },
> > + { .mbps = 750, .reg = 0x09, .min = 689, .max = 813 },
> > + { .mbps = 800, .reg = 0x19, .min = 737, .max = 866 },
> > + { .mbps = 850, .reg = 0x29, .min = 784, .max = 918 },
> > + { .mbps = 900, .reg = 0x39, .min = 832, .max = 971 },
> > + { .mbps = 950, .reg = 0x0a, .min = 879, .max = 1023 },
> > + { .mbps = 1000, .reg = 0x1a, .min = 927, .max = 1076 },
> > + { .mbps = 1050, .reg = 0x2a, .min = 974, .max = 1128 },
> > + { .mbps = 1100, .reg = 0x3a, .min = 1022, .max = 1181 },
> > + { .mbps = 1150, .reg = 0x0b, .min = 1069, .max = 1233 },
> > + { .mbps = 1200, .reg = 0x1b, .min = 1117, .max = 1286 },
> > + { .mbps = 1250, .reg = 0x2b, .min = 1164, .max = 1338 },
> > + { .mbps = 1300, .reg = 0x3b, .min = 1212, .max = 1391 },
> > + { .mbps = 1350, .reg = 0x0c, .min = 1259, .max = 1443 },
> > + { .mbps = 1400, .reg = 0x1c, .min = 1307, .max = 1496 },
> > + { .mbps = 1450, .reg = 0x2c, .min = 1354, .max = 1500 },
> > + { .mbps = 1500, .reg = 0x3c, .min = 1402, .max = 1500 },
> > { /* sentinel */ },
> > };
> >
> > @@ -430,11 +432,18 @@ static int rcsi2_wait_phy_start(struct rcar_csi2 *priv)
> >
> > static int rcsi2_set_phypll(struct rcar_csi2 *priv, unsigned int mbps)
> > {
> > - const struct rcsi2_mbps_reg *hsfreq;
> > + const struct rcsi2_mbps_reg *hsfreq, *hsfreq_prev = NULL;
> >
> > - for (hsfreq = priv->info->hsfreqrange; hsfreq->mbps != 0; hsfreq++)
> > + for (hsfreq = priv->info->hsfreqrange; hsfreq->mbps != 0; hsfreq++) {
> > if (hsfreq->mbps >= mbps)
> > break;
> > + hsfreq_prev = hsfreq;
> > + }
> > +
> > + if (hsfreq_prev &&
> > + ((mbps - hsfreq_prev->mbps) <= (hsfreq->mbps - mbps)) &&
> > + (hsfreq_prev->max >= mbps && hsfreq_prev->min <= mbps))
> > + hsfreq = hsfreq_prev;
>
> Would it be possible to rework this to get rid of the mbps variable from
> strcut rcsi2_mbps_reg? I'm thinking of making the logic selecting the
> first entry in the table where mbps argument falls between the min and
> max values introduced in this patch.
>
> >
> > if (!hsfreq->mbps) {
> > dev_err(priv->dev, "Unsupported PHY speed (%u Mbps)", mbps);
> > --
> > 2.7.4
> >
>
> --
> Regards,
> Niklas Söderlund

--
Regards,
Niklas Söderlund