Ben Chuang 8c68b5656e mmc: sdhci-pci-gli: GL9767: Fix low power mode on the set clock function
On sdhci_gl9767_set_clock(), the vendor header space(VHS) is read-only
after calling gl9767_disable_ssc_pll() and gl9767_set_ssc_pll_205mhz().
So the low power negotiation mode cannot be enabled again.
Introduce gl9767_set_low_power_negotiation() function to fix it.

The explanation process is as below.

static void sdhci_gl9767_set_clock()
{
	...
        gl9767_vhs_write();
        ...
	value |= PCIE_GLI_9767_CFG_LOW_PWR_OFF;
        pci_write_config_dword(pdev, PCIE_GLI_9767_CFG, value); <--- (a)

        gl9767_disable_ssc_pll(); <--- (b)
        sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);

        if (clock == 0)
                return;  <-- (I)

	...
        if (clock == 200000000 && ios->timing == MMC_TIMING_UHS_SDR104) {
		...
                gl9767_set_ssc_pll_205mhz(); <--- (c)
        }
	...
	value &= ~PCIE_GLI_9767_CFG_LOW_PWR_OFF;
        pci_write_config_dword(pdev, PCIE_GLI_9767_CFG, value); <-- (II)
        gl9767_vhs_read();
}

(a) disable low power negotiation mode. When return on (I), the low power
mode is disabled.  After (b) and (c), VHS is read-only, the low power mode
cannot be enabled on (II).

Reported-by: Georg Gottleuber <ggo@tuxedocomputers.com>
Fixes: d275435551 ("mmc: sdhci-pci-gli: Set SDR104's clock to 205MHz and enable SSC for GL9767")
Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Tested-by: Georg Gottleuber <ggo@tuxedocomputers.com>
Cc: stable@vger.kernel.org
Message-ID: <20241025060017.1663697-1-benchuanggli@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2024-10-28 12:27:11 +01:00
2024-09-01 20:43:24 -07:00
2022-09-28 09:02:20 +02:00
2024-10-09 12:47:19 -07:00
2024-10-13 14:33:32 -07:00
2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%