diff options
author | Tony Lindgren <tony@atomide.com> | 2021-09-21 12:42:25 +0300 |
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committer | Tony Lindgren <tony@atomide.com> | 2021-09-21 12:42:26 +0300 |
commit | 95ec14faac6a44bd233c54666722ef75b2276512 (patch) | |
tree | f071f606de9a263e8fe5c44e3848a9c5ef7234e4 /drivers/bus/ti-sysc.c | |
parent | b3e9431854e8f305385d5de225441c0477b936cb (diff) | |
download | linux-95ec14faac6a44bd233c54666722ef75b2276512.tar.gz linux-95ec14faac6a44bd233c54666722ef75b2276512.tar.bz2 linux-95ec14faac6a44bd233c54666722ef75b2276512.zip |
bus: ti-sysc: Check for lost context in sysc_reinit_module()
There is no need to restore context if it was not lost. Let's add a new
function sysc_check_context() to check for lost context. To make use of it,
we need to save the sysconfig register status on enable and disable.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'drivers/bus/ti-sysc.c')
-rw-r--r-- | drivers/bus/ti-sysc.c | 60 |
1 files changed, 49 insertions, 11 deletions
diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c index efd8f0f7cfe3..9e958343a719 100644 --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -132,6 +132,7 @@ struct sysc { struct ti_sysc_cookie cookie; const char *name; u32 revision; + u32 sysconfig; unsigned int reserved:1; unsigned int enabled:1; unsigned int needs_resume:1; @@ -1135,7 +1136,8 @@ set_midle: best_mode = fls(ddata->cfg.midlemodes) - 1; if (best_mode > SYSC_IDLE_MASK) { dev_err(dev, "%s: invalid midlemode\n", __func__); - return -EINVAL; + error = -EINVAL; + goto save_context; } if (ddata->cfg.quirks & SYSC_QUIRK_SWSUP_MSTANDBY) @@ -1153,13 +1155,16 @@ set_autoidle: sysc_write_sysconfig(ddata, reg); } - /* Flush posted write */ - sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]); + error = 0; + +save_context: + /* Save context and flush posted write */ + ddata->sysconfig = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]); if (ddata->module_enable_quirk) ddata->module_enable_quirk(ddata); - return 0; + return error; } static int sysc_best_idle_mode(u32 idlemodes, u32 *best_mode) @@ -1216,8 +1221,10 @@ static int sysc_disable_module(struct device *dev) set_sidle: /* Set SIDLE mode */ idlemodes = ddata->cfg.sidlemodes; - if (!idlemodes || regbits->sidle_shift < 0) - return 0; + if (!idlemodes || regbits->sidle_shift < 0) { + ret = 0; + goto save_context; + } if (ddata->cfg.quirks & SYSC_QUIRK_SWSUP_SIDLE) { best_mode = SYSC_IDLE_FORCE; @@ -1225,7 +1232,8 @@ set_sidle: ret = sysc_best_idle_mode(idlemodes, &best_mode); if (ret) { dev_err(dev, "%s: invalid sidlemode\n", __func__); - return ret; + ret = -EINVAL; + goto save_context; } } @@ -1236,10 +1244,13 @@ set_sidle: reg |= 1 << regbits->autoidle_shift; sysc_write_sysconfig(ddata, reg); - /* Flush posted write */ - sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]); + ret = 0; - return 0; +save_context: + /* Save context and flush posted write */ + ddata->sysconfig = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]); + + return ret; } static int __maybe_unused sysc_runtime_suspend_legacy(struct device *dev, @@ -1377,13 +1388,40 @@ err_allow_idle: return error; } +/* + * Checks if device context was lost. Assumes the sysconfig register value + * after lost context is different from the configured value. Only works for + * enabled devices. + * + * Eventually we may want to also add support to using the context lost + * registers that some SoCs have. + */ +static int sysc_check_context(struct sysc *ddata) +{ + u32 reg; + + if (!ddata->enabled) + return -ENODATA; + + reg = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]); + if (reg == ddata->sysconfig) + return 0; + + return -EACCES; +} + static int sysc_reinit_module(struct sysc *ddata, bool leave_enabled) { struct device *dev = ddata->dev; int error; - /* Disable target module if it is enabled */ if (ddata->enabled) { + /* Nothing to do if enabled and context not lost */ + error = sysc_check_context(ddata); + if (!error) + return 0; + + /* Disable target module if it is enabled */ error = sysc_runtime_suspend(dev); if (error) dev_warn(dev, "reinit suspend failed: %i\n", error); |